Mnemonic Sliver

Lightning Blast deals 4 damage to any target.

(T: Add W.)

(T: Add B.)

Buyback 2 (You may pay an additional 2 as you cast this spell. If you do, put this card into your hand as it resolves.) As an additional cost to cast this spell, sacrifice a creature. You gain life equal to the sacrificed creature's toughness.

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)

Flying As this creature enters, sacrifice any number of creatures. This creature's power becomes the total power of those creatures and its toughness becomes their total toughness. R: This creature gets +1/+0 until end of turn.

This land enters tapped. T: Add C. T: Add W or B. This land deals 1 damage to you.

W, T: Tap target creature.