- Awesome Music: All of the hymmnos songs are fantastic. Special mention to the ending song, Phantasmagoria.
- Best Known for the Fanservice: Among non-fans and even some casual fans, the series is very well known for the sheer amount of fanservice and innuendos it contains. Qoga gets this treatment worst of all, due to stripping being an actual game mechanic. Some parts of the fanbase are a bit resentful of this, as it gives the games an unfortunate reputation in the eyes of the public.
- Complete Monster:
- Bourd Rade is the second-in-command of the Tenba Organization, which is notorious for its shady practices. Rade has a penchant for using innocent people in his army, and lets them abuse the Reyvateils they capture. Seeking to dissolve all of the organizations to get what he wants, he worked with Bishop Falss to awaken Mir. To do that, he first stole the song, Chronicle Key, from the Star Singer Misha, to prevent her from performing her ritual which would keep Mir's seal intact and kidnap Misha to be his personal weapon, even burning down an innocent village. One day, Bourd was to told to meet with Lyner by Falss and tries to forcefully recruit him. After chasing him and Misha in an airship when they escape, Bourd takes another Reyvateil named Aurica as a hostage and threatens to throw her off until Misha returns to his side, and when she does, Bourd throws Aurica off anyway. When Lyner and his group goes to stop Mir, Bourd tries to stop them from heading to their destination, only to end up seemingly killed by Misha; he survives and continues to antagonize the party through attacks. After entering Bourd's secret lab, Bourd reveals to the heroes that his goal is to create an army of lifeless Reyvateils under his command and use them to destroy every organizations, including Falss and his church. Escaping from them, he is encountered one last time trying to prevent the newly regained Chronicle Key from being sung.
- The aforementioned Bishop Falss is the seemingly kind and friendly leader of the Church of Elemia, but as his name suggests, he is wearing a false facade to hide his true colors. From Platina, Bishop Falss's true identity is Kyle Clancy, one of the leaders of Platina who became obsessed with power. Believing he could use the Mother Virus Mir to bring forth prosperity and glory, he tried to awaken her only to get caught and banished by his fellow leaders Shurelia and Leard. After trying again and getting caught again, instead of facing his crimes, Kyle threw himself off Platina and landed on the lower world where he changed his name to Falss. After gaining leadership of the Church of Elemia due to his advanced knowledge from Platina, he began manipulating everyone to bring forth Mir's awakening, from his deal with Bourd, to twisting the Church, to declaring war against Platina to get revenge on them and eliminating anyone who might stand against him, even his own allies. Having returned to Platina during the war, Falss manages to awaken Mir and gain her power, which he uses to try kill the heroes.
- ~arpeggio spinoff manga: The seemingly-kind scientist Masticus is the Big Bad of the story. Having a deep hatred of non-humans like the Reyvateils, blaming them for two apocalyptic disasters in the past despite humans playing a strong role in them, he aims to fully control all of them. Unleashing the Reveris virus, which caused Reyvateils to go berserk or become comatose, Masticus plans to study the virus itself and find the Hymn Crystal "Soporific" in order to perfect. When Espada's father had the Crystal inside his sword, Masticus sends out the living prototype of the virus, Kauron to retrieve it and kill Espada's father and his wife. Once Sonnet manages to retrieve the sword from Espada, Masticus begins showing his true colors, as he reveals that Sonnet is his latest version of the virus, and with the stone, Masticus transforms her into the perfect version of the virus and has her try to kill her two friends Espada and Adagio when they came to see her. Once Sonnet was able to break free, the virus manifests itself into a new physical form, and under his command Masticus orders the death of those who stand in his way. Once the virus is dealt with, he was asked to surrender, only for him to laughs at the heroes for their ideals before throwing himself to his death as one last attack. A hateful scientist, Masticus pretends that he fights for humanity side, but in actuality just wants to satisfy his hatred towards non-humans and humans who support them.
- Game-Breaker: Not really needed considering you have the Reyvateils doing the damage more than your vanguards, but you can actually make anyone (though Lyner gets to use his Wind Slash even before going through the first level of the battle phase) into a Glass Cannon capable of dealing up to 25,000 points of damage. Of course, said party member dies after one hit. The real game breaker though is when you revive them, the person revived gets to act immediately on their turn. Long story short, Wind Slash everything into oblivion. Of course, you do get called out by your current Reyvateil whenever you rest at a camp.
- Ho Yay: Ayatane's relationship with Lyner is a little too close for mere friends. Carries over into Cross Edge.
- Moe: Saki certainly looks this way. Not to mention the series in general draws upon a wide variety of things considered "moe" in some form or another - and even parodies them with the attack item Moe Firepowder in Metafalica.
- Redemption Quest: What this series could be considered as for Mir.
- Suspiciously Similar Song: The music track Sleipnir resembles the Pyramid Cave music from Sonic Adventure 2.
- Tear Jerker: "Mir, all this time you were really just an innocent little girl."
- The Woobie: All three of the heroines in various ways.
YMMV / Ar tonelico: Melody of Elemia