Renolock used to be a T1 deck in wild, and I used it to climb to rank 5. After standard was introduced, Renolock somehow ended up in the shadow of other decks such as tempo warrior and midrange shaman. However, I've been playing around with some cards, and have come up with a N'Zoth Renolock which I like a lot.
Basically, this deck plays like a typical N'Zoth Reno deck; however, it has notably more early game.
Generally, this deck looks to have strong board control from the start, before relying on removal spells in the midgame and large deathrattle minions in the lategame.
Mulligan hard for your earlygame, however cards like Twilight Drake can be kept in control matchups.
TLDR, N'Zoth Renolock with a bunch of earlygame minions. Enjoy.