Animal Motifs: Frequently, as many nations and/or armed forces have animals as their symbols. Most reoccurring, their songs often refer to Nazi Germany and its armed forces as "The Eagle" (one of their symbols). Other examples include (but are not limited to) the Swedish Empire's Eagle and Lion, the Chasseurs Ardennais boar, and the Brazilian Expeditionary Forces' smoking snake.
Audie Murphy: To Hell and Back, named after his autobiographical movie, is about the man himself.
The Art of War: The album of the same title is strongly inspired by the work of Sun Tzu. The title track is all about it and nearly every track on the album opens with a woman reading excerpts from The Art of War.
Badass Army: The Carolean's Prayer paints the soldiers under Charles XII as this, which is Truth in Television and the whole album has the Swedes being total badasses and winning except when they're outnumbered, which is still factual.
Band of Brothers: Union (Slopes of St. Benedict) is more about this than the Battle of Monte Cassino.
The Carolean's Prayer paints the entire army of Charles XII as this.
Being Good Sucks: Most of the heroes from the same-titled album suffered pretty terrible fates in spite of their heroism. Karel Janoušek (Far From the Fame) and Witold Pilecki (Inmate 4859) were both executed by communist regimes. A theme of the album is also that despite their heroism, their tales are mostly forgotten.
Bilingual Bonus: Attero Dominatus uses four words in Latin. “Attero Dominatus” most likely means “Destroy Tyranny”
And Uprising has one sentence in Polish - “Warszawo walcz!” which means “Warsaw fight!” (imperative, i.e. commanding the city to fight - which it did.)
They constantly use German throught most WW2 themed songs, although mostly basic terms everyone knows like "Panzer" (using the entire word "Panzerkampfwagen" in Screaming Eagles). In Rise of Evil, which themes Hitler's uprising to power and the development of Nazi Germany, they use words like 'Anschluss' (the annexing of Austria), and 'Lebensraum' (the initial, official motivation for the war). There is also a cover song of Warlock's Für Immer, which apart from a part of the chorus that's in English and Spanish, is entirely in German.
"Gott Mit Uns." It's German for "God With Us," and was used a lot in the Thirty Years War.
Carolus Rex in general has a lot of this, with song titles like Gott Mit Uns and Ruina Imperii and whole lines in some songs being in Old Swedish. Plus, there is a Swedish version of the whole album. Ruina Imperii is the only song on the album that doesn't have an English version, not counting bonus tracks. The "chanting" in The Carolean's Prayer is the Lord's Prayer in Swedish.
Resist and Bite features "Gloria fortis miles" which means "Glory to the brave soldier" and "Adversor et admorsus" which means "Resist and Bite".
In "Smoking Snakes", there's one line sung in Portuguese: "Cobras fumantes eterna é sua vitória!" ("Smoking Snakes eternal is your victory!"). In fact, throughout the song, they're always refered as "Cobras Fumantes" (Portuguese for Smoking Snakes).
"Hearts of Iron" has a line that goes Nicht ein Schlacht, ein Rettungsaktion, meaning "It's not a battle, it's a rescue operation''.
Cameo: Actor Peter Stormare and Polish general Waldemar Skrzypczak took part in making the video for Uprising respectively playing a commander of the German occupying forces and one of the Warsaw Uprising's leaders.
Blood Knight: "A Soldier of 3 Armies" states Lauri Torni is "addicted to the war game!"
"Merciless killing your own" "A slave to power- a slave to gold. Ruinous rule in the East."
Central Theme: Forgotten heroism is a recurring motif in Heroes, with nearly half of the songs commenting that their titular heroes are rarely remembered. One of the people on the album, Leslie "Bull" Allen lacks an English Wikipedia page and Karel Janoušek only got an English Wikipedia page when the album was announced.
The album Heroes is called that for a reason; ten songs, only five are about groups. The other five are about individual legendary soldiers; Witold Pilecki, Audie Murphy, Leslie "Bull" Allen, Lauri Allan Törninote Larry Thorne, and Karel Janoušek.
Curb-Stomp Battle: Some of their songs, notably Reign of Terror and Wolfpack, are about these.
Killing Ground is this for the Swedes towards the Russians. The next song on the album, Poltava, reverses their positions.
Dark Reprise: While the lyrics certainly do not reflect it, Ruina Imperii is this to Lion From The North, both when you notice that the chorus of the first is more or less a very downtrodden version of the other, and that while Lion From The North covers the rise of the Swedish empire, Ruina Imperii covers its fall.
Dawn of an Era: Lion From The North is about the beginnings of the Swedish Empire under Gustavus II Adolphus. It's very hopeful and energetic.
Death from Above: Firestorm, Nuclear Attack, Night Witches and Firestorm, the last of which even drops the trope name:
La Résistance: Uprising is a song about the Warsaw Uprising, praising Polish resistance.
From the underground,
rose a hope of freedom as a whisper.
City in despair, but they never lost their faith.
Women, men and children fight,
they were dying side by side.
And the blood they shed upon the streets,
was a sacrifice willingly paid.
Coat Of Arms paints the whole Greek nation as this. Considering how tough the Greeks resisted the Axis in real life, this isn't far off.
Saboteurs is about the Norwegian resistance fighters sent to destroy the Telemark heavy-water plant.
Inmate 4859 is about Witold Pilecki, soldier of Polish Armia Krajowa resistance, prisoner (No. 4859) in Auschwitz-Birkenau Camp, leader and hero of resistance in Auschwitz-Birkenau Camp.
Large Ham: Joakim Brodén is a Metal vocalist, after all.
Last Stand: Hearts of Iron is about the German forces of the 12th and 9th Armies, who facing defeat at the hands of the Soviets, created a corridor across the Elbe to protect fleeing refugees and soldiers to escape and surrender to the West rather than face certain death. In the same album, "Smoking Snakes" talks about three Brazilian soldiers note Arlindo Lúcio da Silva, Geraldo Baeta da Cruz and Geraldo Rodrigues de Souza who, ambushed by Germans, fought until their ammo ran out and died in a bayonet charge.
Let's Fight Like Gentlemen: "No Bullets Fly", which is about the Charlie Brown and Frans Stigler incident, in which a heavily damaged B-17 stumbled upon an enemy. However, the enemy in question (Frans Stigler) saw that the ship was too damaged to fight, and promptly not only didn't fire but led the ship to safety. Quote the chorus:
Fly, fighting fair!
It's the code, of the air!
Brothers, Heroes, Foes
Lyrical Dissonance: The Final Solution. An awesome metal song... about the horrors of the Holocaust, specifically Auschwitz. The band no longer plays that song live because they found it unsettling to see the audience cheer and headbang along.
The Price of A Mile, also a catchy, badass, upbeat song about the soldiers dying pointless deaths at Passchendaele.
Mood Whiplash: The album Carolus Rex goes through this at two points. The first, when after thr triumphant and blood-pumping Gott Mit Uns we go into the Tear Jerker ballad A Lifetime At War. The second when after the hopeful tone of The Carolean's Prayer, Carolus Rex and Killing Ground we get the fast-paced yet noticeably down-turn Poltava culminating in Long Live the King and Ruina Imperii - mournful cries about the death of Swedish glory. Heroes has another example with the rather abrupt switch from the blood-pumping Smoking Snakes to the operatic, grim tale of Witold Pilecki of Inmate 4859.
Number of the Beast: Played for Laughs by "A Secret" which contains a part that says that it has detected an illegal download and is executing spyware protocol 666. Note that 666 is spelled out at "Six hundred sixty-six."
Perspective Flip: Most of Carolus Rex is sung from the perspective of the Swedes. However, Poltava includes some parts that are from the Russians' perspective, and the English version of 1648 is from the perspective of the Bohemians. The Swedish version of 1648 is from a Swedish perspective, which also makes the two versions Perspective Flips of each other.
An interesting variation happens in Heroes. Sabaton has a song named "Attero Dominatus" about the fall of Berlin, in Heroes we have "Hearts of Iron" which is about the same event, but from the perspective of the German troops trying to protect civilians.
Power Ballad: "The Ballad of Bull", which is remarkably slow and barely features guitars in it.
Attero Dominatus too, especially if you know what the Soviets did to Berlin... note One of the largest mass rape and murders by military forces on non-combatants in history. Some reports say that every woman between EIGHT AND EIGHTY was raped by Soviet Soldiers
Recruiters Always Lie: In "In The Army Now", the recruiter says that Army doesn't do much except stay in bed, and that the recruit will be a hero to the neighborhood. Nothing like it happens; he's thrust into a war and nobody really cares about him.
Religion Rant Song: Subverted with "Burn Your Crosses". If you hear it without context, you would think it's just a rant on the evils of Christianity. But Joakim Brodén has empathetically stated the song is, like all other Sabaton songs, a narrative: It's about a man about to be executed by the Spanish Inquisition who decides to go out in a blaze of glory, and the song is his speech.
The Lion From The North, which is entirely about King Gustavus II Adolphus, the man who kicked basically all of Europe's ass for a few years.
Say Your Prayers: Subverted in The Caroleans Prayer. The chorus is The Lord's Prayer in Swedish, but it's triumphant instead of resigned.
Shell-Shocked Veteran: Mentioned in "To Hell and Back" and shown in full extent in the music video for "To Hell and Back", which focuses on a PTSD-ridden war vet (implied to be Audie Murphy himself) clashing with the memories of the horror of war. Truth in Television, as Audie Murphy had severe PTSD and helped to raise awareness for the disease.
Shown Their Work: Besides the accuracy (and sheer obscurity) of their songs (such as Far from the fame's Karel Janoušek, who didn't have a english wikipedia page before the single came out), there's a particular example in "To Hell and Back": The song's chorus and a whole verse are lifted almost entirely from one of Murphy's poems.
Snow Means Death: Ruina Imperii, covering the Carolean Death March and the fall of the Swedish empire.
"White Death": the Finnish sniper Simo Häyhä in the Winter War.
Song Of Song Titles: Metal Machine is so full of Shout-Outs to other bands that it'd probably be quicker to watch this video showing what and where they are in the song than to read a full list of them.
That said, its somewhat fitting that a song about their love of metal also has a direct "fuck you" to Metallica's album St. Anger.
Heroes features Man Of War, fittingly for a giant tribute to Manowar, has lyrics entirely composed by names of Manowar songs.
In another case, 7734 from their 2007 album Metalizer is a bonus track on Heroes. It is viewed by many fans as thousands of times better than the original version.
Villain Song: More like "Antagonist Song" as the album doesn't paint them as villains: "Carolus Rex" is mostly told from the perspective of the Swedish Empire and its kings, with the a notable exception in Poltava, whose bridges are sung from the perspective of the Russian troops and their Tsar gloating about how they trounced the Swedish Troops at Poltava.
Listen, excuse for a king. Trust me, this fight you can't win
Listen, obey my command. Hear me, or die by my hand
Madness, curse your feeble horde. Fear me, you'll die by my sword
War Is Hell: Angels Calling, The Price of a Mile and Cliffs of Gallipoli.
A Lifetime Of War provides two different perspectives on the Thirty Years' War. The English lyrics focus on the horror of the war as a whole and the ambitions of the people behind it, while the Swedish lyrics show it all from the eyes of a common Swedish soldier who leaves his friends and family behind to serve his nation with no guarantee that he will ever return alive, or if he will be remembered and mourned.
World War II: One of their common themes, as many battles they sing about took place in that time period.
Worthy Opponent: "Smoking Snakes" retells the story of three Brazilian heroes who fought to their last against the German troops. The Wehrmacht was so impressed it buried them with full honors and wrote in their graves "Three Brazilian heroes".
You Are Number Six: "Inmate 4859", a polish soldier who infiltrated Auschwitz to command an uprising from within and tell the world of the horrors going on there.
We were told to hold the border, and that is what we did!
Honored our orders in despite of our foes!
Hearts of Iron combines this with Last Stand. It's about the German 12th and 9th Armies,who against the Soviets, created a corridor across the Elbe to protect fleeing refugees and soldiers to escape and surrender to the West rather than face certain death.
"40:1" - the story of the Battle that became known as the Polish Thermopylae:
Soldiers of Poland, second to none Wrath of the Wehrmacht brought to a halt.