Sephiroths Intervention Whether Sephiroth's Intervention or Vayne's Treachery is better will depend on if Im right about the formats speed
Calgar's ability is also better for getting cards than Greyfax's, as you don't need to faff around with getting a Clue token and paying even more to sacrifice it Calgar just gives you a draw instead
A player loses the game after having been dealt 21 combat damage from any one of them, not from both of them combined (although your Background won't usually be a creature anyway)
It doesnt kill bigger stuff, so you will often have creatures you wanted to sweep that didnt
What matters about these summons is that they are saga creatures
Blink effects, removal, cheap warp abilities like Haliya, Guided by Light, Treasure, and many other simple interactions will ensure you can auto-equip this card on multiple turns