Which level 7 creature is the best, and why?

In a one-on-one battle, the Ancient Behemoth defeats the Archangel. That's how it is.

Hmm... well, I suggest the following alternative:
Let's play a game where you use a hero with 1 Ancient Behemoth, and I'll use a hero with 1 Archangel. :) In case of a morale loss, we'll have to replay, of course. The heroes should be some Elementals with zero Attack and Defense stats.
And when you lose (and you will lose), you'll write in large text that the Archangel is unmatched in single combat. :)

Because, frankly, I'm tired of seeing such statements, especially after so many pages of discussion and clearly not from a newbie in this game.