Barbarian

Note that there are no gods on the seventh level in any of the castles (a little trivia - the devil is not the highest being in Hell! (Satan is the highest!). The Tower has a Titan, not Zeus! Humans have an angel, not a God! And so on!

Nonsense. Monsters are not gods, they are just animals.

Regarding the arguments: it's all about perception. People are used to thinking that a troll cannot defeat a dragon. These are common truths in all fantasy worlds. And then some original person claims that a troll is stronger than a dragon! Naturally, this is not accepted. Because it's like putting a griffin or, say, a gargoyle on the 7th level. And a troll definitely doesn't fit here.

But a mountain giant - an ancient giant would be suitable - because the word "giant" sounds good, although the appearance can be almost unchanged.

But mountain giants will be gray and boring, like trolls, but there are beloved monsters that have already gained popularity.