I'm a fan on this one. Maybe it's a bit OP but the idea is cool. 1 turn Immunity means that the effective way to counter is to strike back and create another major threat. Though, maybe it shouldn't be enchanted after killing a champion? And only have range 2 minion attack? Idk but it needs some kind of debuff.... balance isn't really part of this tournament and I don't think it's broken enough to kick it out of the tournament so it doesn't affect your score, but it's borderline broken.

Inspires fear from across the field - 7 It has a lot of power...
Breaks common chess intuition with a surprising move - 4 Not that surprising, but that enchant effect can surprise you
Causes aggressive matches - 10