After a bunch of testing, I have decided to use Dr. Ciel's suggestion to add in Forretress and Rotom-W. I am still considering Fire Blast over Rock Slide, but am not sure right now.
This of course means I'm less dependent on Deoxys-D to set up spikes. Adding in Garchomp (suggested by Jirachi) was a nice choice, as his late-game presence is very nice.
Thanks for all the rates!
I'm probably not going to update this RMT, so thanks again for all your help!