Loxi: This could be pretty neat as a flashback/"cast spells from your graveyard" commander, but I do agree that only once per turn makes this tricky if you don't have ways to copy the trigger, and at that point you're really jumping through some hoops
Meanwhile, the Vivi Ornitier card not only gains a +1/+1 counter every time a player casts a noncreature spell, in doing so dealing a single point of direct damage every time he does, but also add any combination of Blue or Red mana, as determined by the Black Mages current power, any time they wish
It gains counters both when it attacks and when creatures it damages die, but the mana cost makes it harder to slip into multi-color builds (good for devotion, though!)
Final Fantasy has four Collector decks, and they are themed in terms of art, mechanics, and even which Final Fantasy game they are influenced by, and each of the decks has all new art, even for the reprints
In particular, you don't get to play a land as Explore resolves
Each of these commanders supports a distinct playstyle, but all three represent reliable foundations for building a strong Zombie Commander deck that performs well across different tables