Episode 20 is mostly spent exploring Evangelyne's psyche.
Sadlygrove gets one two episodes later.
Deadly Dodging: Another use of Yugo's portals, by going through them or having the enemy going through them. A good fighting tactic against Igôle in episode 21, which finally results in the beast going down a chasm. This only slowed it for a while, though.
Sadlygrove's sword slashes often go according to this, but they split stuff immediately just as often according to Rule of Drama. For example in episode 20, when he slices up the arthropod monster in Evangelyne's dream.
Also, the snow sculptures sliced in halves by Ruel in episode 17.
Remington's boomerang has this effect on buildings.
Demonic Possession: Shushu guardians technically exist to prevent this from happening, but Sadlygrove is not very good at it, and has been possessed by Rubilax on more than one occasion.
In episode 6 Vampyro is revealed to be Shushu guardian Wagnar, corrupted by Shadofang.
Rubilax has also possessed Amalia's vegetal doll in episode 7.
In episode 25, Rubilax possesses Sadlygrove once more, but left him in control, since the possession was consensual this time.
Grany Smisse has this happen to him on purpose in season 2.
In season 2 episode 2, we learn that Rubilax had taken complete control of Sadlygrove's human body, leaving Sadlygrove trapped inside of Rubilax's sword. This is remedied a few episodes later.
Anathar was the Shushu possessing the Justice Knight's father. Anathar later does the same thing to Adamai.
In episode 25, when Sadlygrove dies. Everything from Eva's reaction, to the fact that even Rubilax is visibly saddened by it combines to create an utterly crushing moment. And as if to defy the very idea of a Despair Event Horizon, it proceeds to get even worse.
Nox manages to cross it twice. The first time when he finds out his wife and children are dead, which causes the entire events of the first season, and the second when he finds out that despite all the effort he went through to go back in time to prevent said deaths, that ultimately his plan was impossible and that all the people he killed will not only stay dead but that all his effort was for nothing. This drives him to kill himself.
Twice in episode 25. First when Ruel saves Eva and Amalia from Razortime by crushing his arm with his Drill Tank out of nowhere, and second when Master Joris saves now the three of them from Nox's creation by destroying it with a single hit. Both were conveniently too late to prevent the death of everyone's favorite Idiot Hero.
The whole ending in general. Nox possibly kills Yugo and starts up the time machine. However, he learns too late that he didn't have nearly enough Wakfu to go back hundreds of years, only 20 minutes. The only reason his plan failed was because there was no possible way that he could have amassed enough Wakfu.
Devour The Dragon: Rushu devours his entire army for a power boost when he realizes Goultard is stronger than him.
Did You Just Punch Out Cthulhu?: Goultard kicks Rushu's ass almost effortlessly until the latter devours his entire Shushu army for a power boost. Even then, Goultard holds his own and musters enough strength to trap them both in the Shushu realm.
Distracting Disambiguation: While fighting a villain named "The Black Raven", Yugo makes the point that all ravens are black. The team then immediately drops what they're doing in order to work on a better name for him.
Yugo in season 2 episode 4, "Sadlygrove's Return".
Ruel in season 2 episode 5, "The Dragon-Pig".
Divine Intervention: Spoofed in episode 16 when Ruel asks Enutrof himself for a miracle to avoid being eaten by Grougaloragran, promising to "double his offerings" if his prayer is answered. This results in Enutrof manifesting with a ray of light to tell Ruel that "Two times zero still equals zero".
Does This Remind You of Anything?: In the episode "Cleophelia", Sadlygrove tries to use Rubilax in the ring (by making him grow bigger). After a couple of failed attempts, he adds "I'm sorry, this is the first time this has happened to me."
Amalia is most usually barefoot (except during both Gobbowl arcs, in the polar region in episodes 17-18, or when dressed in full princess regalia).
Sadlygrove seems to have lost his shoes sometime after episode 22.
The Doll Episode: Nox shows his talent for mechanical puppet shows in the bonus episode, but that was just the precursor to his puppet shows recreating his family life before he found the Eliacube in episode 24. Logically it should be touching that he's made a puppet show to remind him of that, but it's just really, really creepy.
Do Not Taunt Cthulhu: In season 2 episode 9, Sadlygrove quickly learns that lacking respect for Rushu is suicidal.
Doomed Hometown: Emelka. Within the first episode, it's wrecked by a monstrous possessed berserker and attacked by vengeful forest spirits that turn many inhabitants into plants. Sure, they got better, but then they're paid a visit by a crazy time mage right afterwards...
Downer Ending: The season 1 finale, shockingly for a Saturday-morning cartoon, did not end happily. Sadlygrove, after going through so much Character Development and finally having Evangelyne return his feelings is killed by Nox's Razortime, emotionally crushing Evangelyne and giving Yugo Berserker Tears. Nox himself, having spent the past 200 years draining entire countries to gather the wakfu he needs, is only able to travel back in time twenty minutes, which is not long enough to revive most of the people that he has killed. The result is that due to his insanity, hundreds of thousands of lives have been destroyed for absolutely no reason, with no hope of respite. If you're a fan of Nox, his failure to attain any sort of resolution is just as heart-breaking.
You could count it as a Bittersweet Ending too insofar as the Big Bad has stopped remorselessly killing people and everyone but Sadlygrove survived and Nox's plan to destroy the Sadida ultimately failed. However, some of the moments that made it sweet, like the memorial to Sadlygrove and the Sadida returning to their previous lives, only serve to remind you of the bitter parts. Made sweeter in retrospect when Sadlygrove returns in season 2.
Dragged Off to Hell: Sadlygrove by Rubilax instead of entering Heaven, as seen in season 2 episode 4.
The Dragon: Anathar, to Rushu. He later becomes an actual dragon by possessing Adamai.
Dramatic Gun Cock: A very shotgun-esque one by the bamboo squirt guns in episode 13 of season 2.
Drill Tank: Ruel has one that he uses in episode 25.
Driven to Suicide: Nox in the credits of episode 26. After realizing that the Eliacube won't let him travel 200 years back in time and he has no way of seeing his family again, he simply lies down and dies next to their gravestones. Of course, he was long dead anyway, only kept alive by the power of the Eliacube. His body turns to dust and blows away, leaving only his armour and bandages behind.
Dumb Muscle: The Iop class, including Sadlygrove. The Iop king even uses this stereotype in a positive way, claiming they are not smart enough to consider betrayal.
Dungeon Crawling: A few of the heroes' adventures. The Dragon-Pig's lair in season 2 episode 5 hangs a lampshade on the whole thing, with a map alluding of the traps to come, and a few meta references to online RPGs.
Earn Your Happy Ending: Debatable. On the one hand the overall tone of the season 1 ending fits with this trope, on the other hand the heroes don't actually earn the ending themselves. The villain does succeed in defeating them, but his actual plan fails simply because it never would have worked in the first place, regardless of what the heroes did.
Elemental Powers: Yugo and Nox use space and time, respectively, and the Sadidas control plants (the Chinese element wood). On the minor characters' side, Vampyro (or rather Shadofang) can control darkness/shadows, and (if you really want to stretch the definition of "element") Chouquette can control pastries.
Embarrassing Nickname: Sir Sadlygrove Percedal has a real name much cooler than his nickname, which is either "Grovy" or "Percy" depending on if you subscribe to fansubs or the official English translation. It's even worse in the original French: Sadlygrove's name is originally Tristepin (an almost literal translation), and his nickname is "Pinpin". His master, Goultard, calls him "Pipoun". Guess you can't go lower than that for a fearsome warrior.
In Season 1, the last shot of the opening is Yugo (or Sadlygrove for the episodes focused on his character arc) flying towards a villain whose size is exaggerated for dramatic effect. The villain in question is always that particular episode's Villain of the Week (until the last episode, which uses Nox).
In Season 2, the shot of Ruel throwing his shovel is replaced with Sadlygrove throwing Rubilax after episode 5.
Exactly What I Aimed At: Evangelyne against Remington in season 2 episode 2 — her light arrows didn't miss, she was aiming at crashing a house on him. Same thing with her recall arrow, as she wasn't aiming it at Rubilax like he'd thought.
Sadlygrove often inspires this to his friends, usually accompanied by them calling him a "Iop brain". Eva goes for the two-handed facepalm◊ in episode 19 when Grovy gets himself into a duel with Prince Armand.
Jay the Iop also spurs Kriss Krass to facepalm during the Bontarian Gobbowl match.
Rushu facepalms when he thinks Anathar has just crushed his precious Eliatrope prisoner.
Facial Composite Failure: The poster of Nox's minions done by Renate in episode 24 results in Yugo and Adamaï being fired upon by Crâ border guards.
One of the most drawn-out example is certainly during the Bontarian Gobbowl arc, after the start of the second quarter-time. Grovy seizes the ball to everyone's surprise and runs, along with a very uplifiting music, dramatic echo of Ruel's earlier psych-up speech and Split-Screen Reaction of everybody else... and he scores! Except it is revealed after a few seconds of shocked silence that he scored against his team. Cue the public rolling in laughter, and his teammates barely preventing Ruel from strangling Sadlygrove.
Famed in Story: By season 2, the Brotherhood of the Tofu has gained some renown from defeating Nox, and are sometimes recognized. This is in fact what motivated Cleophelia to desert from the Crâ, seeking to gain fame at least equal to her sister's.
Flower in Her Hair: Amalia. It stays alive due to her Sadida powers, as seen when it begins to wilt in episode 7 after she has been poisoned. As if not enough, she sometimes adds another flower on the opposite side.
Follow the Chaos: In the season 2 finale, Eva is looking for her boyfriend during the battle. Cue a huge nuke-like explosion going off on the other side of the island.
Evangelyne: (deadpan look on her face) Never mind, I found him.
Food Porn: The show sometimes delves into this, with for example Yugo's blanquette or the feast at the end of the Bontarian Gobbowl arc. And then there's the whole of episode 8 and its bakery contest; even its Monster of the Week can make you salivate.
After episode 25, you will not be able to rewatch the "Gobbowl Hell" arc with anything approaching the same frame of mind. The phrase "I'm entering into the legend!" takes on a whole different meaning.
Sadlygrove also mentions his high opinion of a heroic death in Eva's dream in episode 20. He does it again during his rallying speech in episode 25.
There is possible foreshadowing for the end of season 1 as early as episode 2. He tells Yugo "I shall repay my debt, even at the price of my life."
Yugo's talk with Amalia in episode 13:
Yugo: I love the stars. Sometimes it feels like my real home is somewhere up there.
Adamaï has been featured in the opening credits since the very beginning.
The entire point behind the female sacrier in season 2's 10th episode ending credits, and opening scene of the next episode. That, and more Fanservice.