"How valuable is Shadow Claw Gengar?"

#PokemonGO: I have a level 25 Gengar with Shadow Claw and am wondering whether he's worth feeding. His IVs are either 12/14/13 or 13/14/12 (the IV calculator doesn't know for sure).I know that he's great for Psycho Cut/ Focus Blast Mewtwo, but given that there's only a 1/8 chance of Mewtwo having that moveset, I'm reluctant to feed SOLELY for that reason.I know that he's a powerful glass cannon for fighting Psychic types now, but I'm skeptical that I'd like him more than my almost-maxed Bite/Crunch Tyrannitars. Will Shadow Claw Gengar be awesome for future generation Legendaries? Will there be powerful gym Pokemon in later generations where he outclasses Bite/Crunch Tyrannitar?(I have a good set of Tyrannitars ready for non-Focus Blast Mewtwo, in case you're wondering). via /r/TheSilphRoad http://ift.tt/2xNki5a