A couple tidbits about Snoke...
What filled Kylo with absolutely incandescent rage was the thought that Snoke--his Master, the one to guide him away from the duplicitous light, the one he'd looked up to above all others--has been someone's puppet all along.
A flash of lightning illuminated a huge glass tank, containing three creatures, liquid life being pumped into them through mechanical umbilicals. They were all the same create, he realized with a start, with wrinkled skin and an oversized bald head and features caught in a state of everlasting anguish. They were all Snoke. Snoke came from this place. Yet Kylo's former teacher had told him nothing about it.
"Snoke." The Emperor's voice filled with glee. "He was nothing but your test. You did well to destroy him."
Snoke had been nothing more than a pawn. The Emperor had whispered poison to Ben his whole life.