Firstly you should change Kyogre's nature to timid. Base 90 speed needs all the speed it can get so you can go first with water spout. If you are really having trouble outspeeding things then change choice specs to choice scarf.
Necrozma needs a nature, you should put a defence boosting one that doesn't lower attack.
You already have a choice specs pokemon so I think Dialga can be replaced by another dragon type like Eternatus which is faster and has dynamax cannon which can be used more without switching because it doesn't lower special attack, or palkia which can benefit from kyogre's rain more with stab water moves.
Yveltal's evs should be into special attack because you have 2 special moves. Sucker punch is still strong with only 4 attack evs (boosted by dark aura too) and it is mostly used for killing faster things like boosted necrozma and calyrex shadow.
After applying these changes you should test the team for yourself on pokemon showdown to see if it works well.
Hope this helps.
