User blog comment:NicknameMy/Response Rework for the Mordekaiser Rework/@comment-10958553-20150223051516/@comment-3493296-20150224003907

Actually, the tool for Mordekaisers sustain is his shield which blocks the damage you would normally take. And since it no longer decays, it is a reliable tool. And then, either Spellvamp or Warmog's Armor completly nullify them.

Mordekaisers health costs are only there to limit his earlygame, because otherwise, his permanent spamming would be too strong. Lategame, the health costs shouldn't matter at all, as at this point he is balanced around to have no costs and freely spam everything.