The second ability is a recursion that only allows for a Historic (Legend, artifact or Saga) card to be returned, and if it is a creature, its made stronger than before with +1/+1 counters
Trample, haste, annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.) When you cast this spell, for each opponent, gain control of up to one target creature that player controls until end of turn
Doomskar Titan is only a 4/4 itself, but having Foretell allows a player to drop on turn five, which is ideal in Aggro and go-wide cheap/token decks
You draw cards, but the cheaper cards perpetually get youll lose 1 life when you cast it. Perpetually is so simple that lots of digital cards have it, and it can even be used in conjunction with other mechanics like boon and intensity
The current Mega Evolution era added two more tiers on top of this chart, covered next