I don't think they're weak @THEBOYWONDER, if anything C'Thun seems pretty damn strong to me so far. Hardly different than any other tribe, you've a mix of vanilla-at-worst minions and a couple nice perks for staying true to it. The four-drop Divine Shield is, well, I don't think it's the new Shredder like some people have called it but it's competitive. Spider Tank 2.0 is fine, pewpew guy is sometimes better sometimes worse than Argent Horserider which has proven to be quite playable. The two-drop is vanilla and the five-drop is Fen Creeper but it's still a very respectable curve that also pumps C'Thun up +5/+5 or more, and you only need plus-four (10+ Attack) to turn on the really good shit like Twin Emps and Warrior/Druid's godly minions. Then there's C'Thun itself.
Yogg, yeah it's net positive but perhaps too unreliable. That said, it seems to slot in just fine to decks that are already spell-heavy, particularly Tempo Mage and Miracle Rogue, without being a particular focal point of the deck and just being a nice alternative finisher. Yogg is sorta like Antonidas in a way, except class-neutral and you're allowed (encouraged even) to cast your spells in advance of dropping it. On which note, Miracoli seems like it could be making a comeback with additional spell-producing shit and the Owl/BGH nerfs bringing Cleef back into relevancy. I did get hossed by an N'Zoth once too though, I'm interested in seeing more of that develop whether Rogue or otherwise.
New Hogger isn't even better than old Hogger. New Mukla I thought was bad at first, but I realized it's sorta like Toshley except you lose two ass for better "spare parts" (and get both on Battlecry instead of one on Deathrattle). Could be something in the same decks that like Yogg, aka the ones I mentioned above. I don't know why you thought Tentacles for Arms would be good? It's nothing more than a Fatigue Warrior mirror tool for chipping down armor. Will real, actual Fatigue Warrior even work anymore? I feel like C'Thun Warrior will push it to the wayside, if for nothing but Ancient Shieldbearer being a Super Shieldmaiden and C'Thun itself is basically a double Pyroblast even if it just gets Executed. That'll probably get you ahead in the Armor race more than TFA will anyway.
I'm liking the new look of Flood Zoo. Puggy convinced me to try Darkshire Councilman, turns out it's preeeeeeetty gooooooooood, but Forbidden Ritual is easily the best card of its cycle and even Possessed Villager is a welcome additional one-drop to the Warlock crew, what with most of the other sticky minions going away because NAXX OUT
. If you don't run away with the game on the opener as Zoo is often wont to do, you get some huge Turns 4-6 swing opportunities with Ritual repopulating your weakened board or turning on 5/5 Reliquary Seekers and 0-2 mana Sea Giants.