I thought a fun deck to play would be just go all out with chimeratech (fuse it together with 5 monsters) then use half shut on one of your opponents monsters. Though at that point youll probably just end up KOing them anyway lol
I think the only other options would involve Mystic Box + Cannot be Destroyed Monster (Like Obnoxious Celtic Guard). Half-Shut and Impenetrable Attack are the only options we have at the moment. The other options would involve opponent owned effects like Amazoness Queen or Noble Knight + Noble Arms of Destiny.
That should be more than enough considering Chimeratech probably won't be needing to attack more than once. In Duel Links, a 5K LP PVP Format means you only need 7 monsters to make an OTK direct attack. If you can get it up to 8K (10 monster fusion), the duel is most likely in the bag.
I just did the math and it looks like Half Shut makes a 4 monster fusion viable in most scenarios (Using it on a monster with 3900 ATK or under and considering a 5K LP count, Chimeratech takes the game on it's fourth attack.) 3 Monster Fusion is only viable with a monster at 1450 ATK or under.