Your Hero deals its combat damage as Magic Damage instead of Physical Damage.
3M: Deal 3 Magic Damage to target Hero or Companion. You can only use this ability once per turn.
"Not all wizards wield wands."
+1 Attack (A) / +1 Mana (M)
Rai'Zen, Mage Blade
Frequently Asked Questions
Combat damage includes effects like Retaliate as well.
Losing the mana (M) from Rai'Zen will always attempt to take away from your spent mana (M) first.
The active ability can be negated in response by either destroying Rai'Zen or removing it from the game.
If the active ability is negated in response to its activation, then you still have to pay the mana (M) cost.