The actual effect of the card isn't anything special (see: Sokka, Tenacious Tactician), it's really just a matter of whether rulebreaker truly breaks the card or not
I wanted it to be something that the opponent could do, but not easily
Even though he triggers his own token ability there just isnt a deck to build around this Mavren Fein in monowhite since youre forced to send your relatively weak commander into the redzone to get the trigger
With Lion's Eye Diamond or Lotus Petal, you generate infinite mana and cast Brain Freeze over and over, milling yourself and your opponents
Targeted land destruction is often widely accepted, while mass land destruction isnt
When this creature dies, create a 1/1 colorless Thopter artifact creature token with flying for each +1/+1 counter on this creature