Best level 6 unit.

It's not that easy to "assess power," which is why the topic exists. The point of the topic is not to discuss "who is stronger," but rather to discuss abilities (which every creature of level 6 or higher has), the relevance of these abilities, and the relationship between combat parameters and abilities...
Of course, everything is complicated by probabilities (griffins, unicorns, manticores, dark knights)...