RockFall (Need Feedback)

hey there, ever since i did a jund warpworld deck with ob nixilis, ive always felt he needed a home. with the new titans i feel that he now has that home in a gwb deck. the cards i have selected are the cards i have (only 1 green titan and 1 black titan and only 3 white titans, but i do have 4 bsa), but i am up for any changes that can help fuel. ran this @ fnm and went 4-0, but i had to leave early so i dropped before top 8 was counted. anyways, looking for any and all feedback. i realize that ob nixilis could be taken out and black all together, and if need to be i will. but landfall with him i feel i can win, with other win cons such as bsa and sun titan himself. please give all feedback on how to evolve this deck to a better gwb or gwb or maybe even just gw... and i know sb needs work, help here too thanks p.s. with exception of 1 noble, 1 knight of rel, and 1 maelstrom i want to stay standard after rotation, so please try to keep this in mind