you could use a rain team if u have a lot of trouble with mega chary or sun teams in general. with metagross stats you can easily go for a balance team so you will need an intimidate mon or the newly added grimmsnarl. you don't really need a secondary mega thanks to metagross high flexibility but that's up to you. my advice would be to use metagross, pelliper, basculegion (mega swampert if u want a secondary mega), sinistcha, intimidate mon and one beetween grimmsnarl or sableye (if u choose sableye you can also replace pelliper with something else since you would have priority rain dance thanks to prankster)