The win condition strapped to it is nice to play to, and is likely to make it a popular card amongst the more casual players
If your cube is both a) durdle city, and b) low powered ...Then getting the card to work is probably a waste of time and very look-what-I-can-do
Usually, the unknown in Magic is in the opponents hand or their library which is threatening, for sure but what if that element of surprise that could be anything was already on the battlefield, attacking your opponent
Notably, the returned Rats don't need to be among the cards you milled, so if a powerful Rat gets removed, Ashcoat can easily get it back so long as you don't mind milling four cards (and that effect can play into graveyard synergies too)
While it comes with the drawback of dealing two damage to its controller of their end step if they hadn't activated a loyalty ability of a Planeswalker that turn, this drawback is nearly aways a non-factor in Planeswalker-heavy "Superfriends" decks
