Well, I tried it out both ways. The one posted above works well for multiplayer as I have repeatable abilities.
I ended up taking out some stuff though to toss in Counterspells, Consult the Necrosages, Recoil, Clutch of the Undercity. There's better stuff I could put in to make this better, but for now I'm testing it to see if it's worth my time continuing this U/B build or if I should try something different.
Changes went like this:
-1 Riptide Shapeshifter
-2 Aetherplasm
-3 Assassinate (the Sorcery speed bothers me)
-2 Rite of Consumption
-2 Diabolic Tutor
+2 Recoil
+3 Counterspell
+3 Clutch of the Undercity
+2 Consult the Necrosages
If I do continue this build, other improvements that are necessary include a more consistent means to retrieve the creatures I want instead of just topdecking (Diabolic Tutors are still set aside for this. Still trying to find a means to get some Demonic Tutors), more powerful Creatures with better abilities than what a few in the deck have to offer. Namely Phage is something I'm wanting to remove.
I'm looking at getting more Clones, though the downside of going with some things in this deck is what I do against builds that have either weaker creatures or very few creatures. I simply don't have much I can do if the opponent isn't putting big creatures into their graveyard of putting them into play for me to copy. This will be exceedingly detrimental to the deck in some games. I'm thinking I could toss in Rite of Consumption against just so I can sac my own large creatures to deal direct damage, though that is relying on the idea those creatures will actually stay in play long enough to sac. I have severe doubts on this once it gets to Game 2.
To be honest, it works sub par, even for a Casual deck. It relies too much on the critters the opponent is playing to create a Win Condition, which isn't a good thing to be relying on. I do like the idea of using the shapeshifters to copy creatures the opponent controls or that are in any graveyard, as multiplayer tends to see a lot more Fatty action because of the longer game play.
Perhaps I should find a easy to cast means of larger creatures myself so I can Clone those instead. I already have 4 Legendary Creatures in the deck out of about 18 Creatures. I'll have to see what I have for possible substitutions. Maybe a Sphinx of Jwar Isle. Clone doesn't actually target it, per say, so it can become it. Jwar is also harder to kill. That might be a good addition in comparison to something like Phage. By at least several Miles. Makes a good drop from the activated ability of a Shifty Doppelganger too. Hmm...
The current amount of control I have going with the Counterspells, Doomblades, Clutch and Mind Control is causing some grief with the other Casual players in the group though. I know I shouldn't cater to the crowd, but I don't want to be a total a** either. Out of 12 players, probably 9 of them have started playing in the last couple of years, and of those 9 probably 3 of them have knowledge of the rules that is well above average. Teaching them new things is good and all, but being a total jerk about it will just cause issues.
Some days I really hate playgroup politics.