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.
Complete Monster: Redda rarely picks fights with characters that are either weaker or stronger than he is, but that's because he doesn't need to. Instead, he prefers to stick with his mastery of manipulation, which he takes pleasure in using on others, especially to the point of driving them to suicide, and loves subjecting things to disturbing splooshy transformations. And that's not all: he even takes Rockna hostage and sticks her inside Dread Dragon's neck and commands it to create a wormhole that sucks all of Mondo's monster friends inside it, leaving Mondo with a Heroic BSOD, after which it takes him a bit to get better. And thanks to Redda himself, Rockna was ACTUALLY this close to being slaughtered in a truly terrifying way.
Nightmare Fuel: As if Reda's scary death mask that he wears over his hot Bishōnen face wasn't frightening enough, he loves subjecting things to disturbing splooshy transformations as well, such as having Oroboros give such a transformation to the Terror Dragon in order to give Oroboros a new body after the Terror Dragon itself is resurrected by him.