Lightning Axe
Instant
As an additional cost to cast this spell, discard a card or pay 
.
Lightning Axe deals 5 damage to target creature.
Jason A. Engle
Rulings
The mana value of Lightning Axe is 1, no matter which additional cost you paid.
(wotc • 2021-03-19)
Rulings
The mana value of Lightning Axe is 1, no matter which additional cost you paid.
(wotc • 2021-03-19)