Vohar can do a serviceable impression of the classic Merfolk Looter, allowing you to sift through your deck while filling up your graveyard for later
You can do it at the end of a turn and then attack with a big fat army out of nowhere
If theres any virtue to Rhystic Study and Smothering Tithe, they do help a struggling player piggyback on another players success
The main point of polymorphing is to target your own stuff, and this blue instant wants you to pray and hope you deal with an opponents creature without flipping them into something even worse
Three is a very reasonable cost to just cast Biting-Palm Ninja, though the card isnt all that desirable in a Cube that cant facilitate ninjutsu consistently
As far as R&D is concerned, it is the theme discard cards that cause the most unhappiness as discard decks are one of the scary three (land destruction, permission and discard) that tend to keep people from playing the game and thus tend to annoy players at a much higher level than other decks