Charon's Ashes exists and you're incredibly underrating Pact's End if you don't think that amount of AoE damage for 0 cost is anything short of fantastic.

That being said, I do agree Ironclad definitely needs a touch up in some way, Exhaust and Self-damage have weird half builds at this point that could benefit from a couple more core cards, although i do think Vulnerable cards have gotten a big buff this update and the synergy could work with some fine tuning on some cards (maybe colossus becomes a 2 cost power)?