Obsessive Skinner is sweet. It has some flexibility when it enters the battlefield on where to put the +1/+1 counter and late in the game if you can get delirium going it starts to become a long term problem for your opponent. Nice.
Manic Scribe is interesting because it comes down early enough to do some blocking in an attempt to draw the game out, and it even has a win condition built in. But enabling graveyard shenanigans for your opponent may be problematic.
Gibbering Fiend has meets the bat barely on all fronts. It pings the opponent (not their creatures though…) when it enters the battlefield, and is a serviceable 2/1 for two mana. Later in the game it will be really annoying for the durdle decks in the format, but ultimately it’s pretty easy to kill.
Paranoid Parish-Blade tries to transition into the late game and might even succeed. The key question is if a 3/2 for three mana is good enough on its own. If it is, then yay, upside. If it isn’t then waiting to get to delirium is a tall order for a beatdown creature like this.