Don't know if it's meant to be this way but ant mantle of oceans has no mana upkeep.
Also after grabbing a few Mage traits champions/ sovereign I can cast a whole assortment of spells in tactical for free.
The following spells I'm casting without mana cost are heal,shrink,slow,blizzard, haste,growth, ice elemental. I don't know again if it's part of how the game will work but I'm posting it.
