For starters, the commander gives you 1 life every time a creature enters the battlefield
Marshmallon is infinitely better than Spirit Reaper (which saw actual meta play) because you took 1000 damage (thats a whole Dian Keto right there) just for crashing into it the first time, and then all you could do was stare at that taunting, silly smile for the rest of the duel or until the teacher pulled you aside because you were being too loud in the library
If you're playing a lot of small creatures, or maybe a commander like Adeline, Resplendent Cathar , then you'll find a lot of opportunities to draw cards - you might even be able to draw cards on opponents' turns with a bit of creativity
When you do, cast it for its madness cost or put it into your graveyard.) Hellbent Skip your upkeep step if you have no cards in hand
Despite having quite a few powerful and historically relevant cards, the Limited format isn't considered 'bomby'