Something's up with the table.
+1 damage if
:life ,
:life or
mark.
Pleases clarify.
Is the attack given up permanently, or just for a turn? I suggest a slight wording change: Heal target for half this card's damage.
I don't know if that will fit on the card with the rest, but I can't access he image builder at the moment to check.
Anyway, I like it

I wouldn't like it as much if it were a one-time use.