Which level 7 creature is the best, and why?

black dragons are power

Fully agree.

Black Dragon (4000 + 2 Sulfur) Loses to Archangel, Behemoth and Archdevil, draw with Titan, beat the Gold Dragon by a small margin. Brutally burned the rest! Completely ignores magic (simply doesn't believe in its existence!) A very effective unit for fighting players who rely on magic and casting Armageddon, which he also refuses to believe in.

Black dragons lose to Archangel, Behemoth and Archdevil, but they can be easily blinded, and Behemoths are also very slow. Almost always wins against the Titan.