In your opinion, which faction is the strongest in Heroes 5? Let's discuss the advantages and disadvantages of each faction.

P.S. Of course, against Necropolis, Inferno, and partially Academy, Phoenix is useless, but it's very difficult for the others to stop it. And a really strong one can be summoned, and what's even more important, obtained in a guild: Mages, Necromancers, Dungeon, Sylvan.

You can't use Phoenix against Necropolis anyway. There are Death Harbingers for such cases; will you say that you'll destroy them before releasing the Phoenix? And I'll raise them at the right moment and still kill the Phoenix. And the spell costs too much for repeated use.