Einzbern Castle

Einzbern Castle enters the battlefield tapped unless you control a Servant Berserker creature.
{t}: Add {r} or {g} to your mana pool.
{x}{r}{g}, {t}: Target creature gets +X/+0 and gains trample until end of turn.
Since losing the Third True Magic, the Einzbern will
do anything to claim the Grail.