These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Ben 10 Generator Rex Heroes United
Character Rerailment: With the exception of a brief scene referencing Mr. Smoothie, Ben loses most of his silly behaviour during this episode to be a more equilibrated character. He also doesn't call out his aliens' names when transforming.
Moral Event Horizon: you can more or less feel sorry for Alpha's situation until he indirectly kills thousands of evo's.
Nightmare Fuel: Alpha creates his various body by absorbing nanites from other Evos, similar to Van Kleiss in the first season. Except instead of being turned to stone, they are reduced to ashes. Now remember that Alpha did this to various Evos over the special, and some of them might have been humans...
Go to extreme when he goes to the Bug Jarr and absorbs almost every Evos in it.