The key aspect of Monstrosity is that it is a one-time effect
The Pokmon card Sneasel 86/168 of Celestial Storm also exists in Reverse version
Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei, Shizos Caretaker is still on the battlefield. Basically, youre going to fill the deck with cards like Viscera Seer, Zulaport Cutthroat, Yaroks Fenlurker, and Big Game Hunter, and just recur them for all of time until you win the game through sheer force of will and the little people fighting back
As the flavour text notes, they are good allies everywhere except for dinner tables
Or you could use one of my favorite underutilized combo-enhancers, First Day of Class, giving the tokens haste and a +1/+1 counter