The shard Power of Storms gives the hero a 15% chance to rapidly restore mana for 4 seconds. Now all new heroes don't use Mana and the shard does not provide any benefit for their resource gain. I tested it on mystic and she gained not more appeasement when hitting or collecting. The shard says for all heroes which is missleading.
Steps to reproduce:
You either get increased special ressources gain with none mana heroes or it does not say Valid For: All.