I tried playing this scenario – whoever goes first will win with a Priest, provided that both War and Battle skills are maxed out at level 5.
Here's how it works: 1 – the Druid summons Manticores, casts Antimagic or something else on himself. And the Priest casts Regeneration. Now, if the Nature faction continues to summon, the Priest will continue to cast blessings on himself as healing, Heavenly Shield, and Nature's Ward. And if the opponent does, Regeneration will do its job and prevent the Manticores from killing him.