Creature-heavy decks tend to have better stax matchups than turbo-combo-spellslinger strategies because more stax pieces naturally restrict and punish players attempting to cast free spells, generate tons of mana, and so on
Considering that some players are frustrated by Mill in EDH, the fact that his second ability can take players out in a single attack with cards like Fraying Sanity really adds to the salt factor here
The biggest downside to Stuffy Doll is that it's pretty expensive
While not a true Mindslaver effect, Sen Triplets is still a pain to play around and forces you to make some unfavorable plays to deny your opponents access to your spells
His inherent ability is actually one of his best
Im in no way insinuating this is able to compete at a cEDH table!) Ported over from the precon are Tournament Grounds, Godless Shrine, Temple of Silence, Command Tower, Arcane Signet, and Colossal Hammer