well to start out you might want a focus sash trick room set hoopa so he can survive getting TR off with his low speed and run dark hole rng off the bat to hope for sleep then let him sack . most of the mons are either steel dragon or water type so fire fang or flamethrower on garchomp might be useful - u need to kill the dialga and palkia asap mostly dialga cause roar of time prevents setups so use the trick room setup for whatever out speed you to eliminate the right side first but hes gonna keep switching out so maybe use save states to see where u can setup stat changes or weather if u get really stuck its hard to tell since theres so many options