I have not seen such a drastic impact to the game from a hero since Bone Dragon's legendary skill was introduced (which was intended to counter balance the exploitation of max starting energy specific heroes that could immediately wipe out a team).
With this new hero now providing a counter to both void and bone, the game took a step back to it's primitive state and the starting energy exploits are back in full effect (and even worse now with Dungeon Man now available).
We are now beginning to see a blitz of Dragon Slayer + Dungeon Man + max runed starting energy heroes (Dracul, Wee Witch, Moon Drake etc). The game has once again been pushed back to a state of "who ever shoots first wins". A team of Dragon Slayer + Dungeon Man + Dracul (with max starting energy runes) + Hydra + (whoever) will wipe out pretty much any team instantly, regardless of how much shielding and magic defense they have.
I'm not sure how balancing is going to work in the future (maybe not allow certain skills to instant kill a team?) but this hero now breaks the starting energy bandaid Bone Dragon and Void Dragon were implemented to fix.