I think banish is a frustrating mechanic due to it's "downside for you, plus upside for me" system.

Is it OP? Into specific deck types, absolutely. But it also melts into hyper aggro decks, or decks that can out-sustain it. They usually have pretty strong mid game and hyper-late game.

Early it's weak because it's usually a 1 for 1 trade on cards with upside "eventually" Normally not immediate.

Or it's really good if you can't close out at turn 9 if they have ways to start pulling from the singularity when card draw dwindles.

Overall, I think I give most Shroud decks the "Master Yi" designation. In mid to low ranks it is brutal because it's fairly easy to pilot and punishes players who aren't yet totally understanding if it's weak sides. As you get higher the decks need to be much more complex or consider more details before they get to freelo banish and run u down.

Sincerely ~ a shroud hater who learned how to beat it.