Dorn Frostgard, the IceDrag

If you are The Runemaster,you may pay {s}{u/b} instead of paying Dorn Frostgard mana cost.

Double Strike.

Whenever Dorn Frostgard deals damage to player or planeswalker, draw a card. You may discard that card, if you do, create Rune
Totem token.