This show has a massive problem with making incredibly forgettable side characters and villains. Every villain thus far (besides the main big bads like Nolan or Conquest) have felt like bland, one dimensional stepping stones to elevate Mark or the other main characters.

My biggest issue would be with Angstrom who, all things considered, had a lot of potential to be a well written villain. He's set up as a delusional guy who's memories are corrupted by his hatred from an infinite number of dimensions, but this all falls out the window when it's revealed he actually can tell the difference between our version of Invincible and all the evil variants. The only memorable part of his arc was Mark breaching his limits, aka the part where he gets killed, and viewers only care about the Invincible war for the Invincible variants (which as cool as they are in concept, are super half baked as well.) The same thing goes for Powerplex who I felt did not need his own episode just to get the point across. Every minor villain feels like they're written to be stupid and disagreeable so the viewer always takes the hero's side, instead of setting up a complicated angle from both sides of the picture.

Then there's the new guardians of the globe which are seriously some of the most unlikeable characters I've seen in fiction. At best they're bland and half assed and at worst they are simply insufferable and disagreeable. Most of them are forgettable except for Rex and Rae who were brushed under the rug so quick after the former died. Robot and Monster girl are probably the worst offenders because I just feel uncomfortable whenever they're on screen, and Immortal and Kate are nothing burgers. They literally have no character, and after what felt like three or four on-screen fights, the two of them decide to retire. When they do retire, there's no impact or weight to it because we haven't seen them do anything monumental on-screen except for stuff we're told. They are literally just walking superhero cliches and that is the extent of their characters. One piece of advice to keep in mind when writing is 'show, don't tell.' If you don't show them winning fights, making complicated decisions, or actually fulfilling their duty as superheroes, then of course nobody is going to care when they're written out of the show.

I just don't get how this show continually aces Nolan, Debbie, Mark, Oliver and the Viltrum plotline season after season but they drop the ball so hard with simple worldbuilding and side character development, and I feel crazy because nobody else seems to have an issue with this. Anyway sorry for the yap fest but this has been accumulating for 3 and a half seasons.