With stackable buffs like Zenzizenzizenzic that also have a mana upkeep is additional mana upkeep charged for the extra buffs beyond the first one? And if so, how does this extra mana cost work? Is the cost simply multiplied by the number of copies in the stack (at the normal time), or do the extra copies have their own (mana cost) timers that I can't see (or is it some other third thing)?
Each stack has an individual timer. Consecutive castings of ZEN will result in incredible magic power. with the benefits and costs lapsing as each stack times out. Only since the icons stack you don't see all of the timers. The cost is mitigated by the mana regeneration the spell provides. With 3 stacks (the max) you spend 3 mana every 5 turns and regenerate 1 mana every turn. (or regen 2 mana every 5 turns depending on how you want to phrase it.)
