Hi.
I wanted to create a new meta.
I started with Necrozma.
Best partners for Necrozma in you opinion?
first of all you should decide on a set to use for necrozma, but since it is used on hyper offensive teams it has either the power herb meteor beam-set or the lead-set with stealth rocks to lay out some entry-hazards. the movepool is heat wave, meteor beam, photon geyser or psyshock, depending, if you want to catch chansey / blissey, since you hit them harder on their physical side.
common teammates are:
rillaboom: is an extremly good pkmn on hyper offensive teams as its swords dance-set is extremely powerful and after a +2 there are only a limited amount of switchins into its stab grassy glide and its coverage-options in high horsepower or superpower. it can provide momentum with u-turn as well.
hawlucha: paired up with rillaboom, that pkmn builds up a nice offensive core as this can abuse grassy seed to get the immediate boost with unburden and roost, close combat, acrobatics and swords dance is a very great set which also provides longevity.
crawdaunt: is very solid on offensive team structures as it has a massive breaking power with swords dance + 3 attacks with even a strong priority move in aqua jet, the remaining moves are stab-knock off and stab-grabhammer.
primarina: can abuse rillabooms grassy terrain together with leftovers to maintain itself healthy when it uses the substitute + calm mind set. rillaboom with u-turn is a blessing there to get it in on a safer spot, so you can start to set-up. moonblast + scald are the stab options.
toxtricity: this mon recently rises in popularity and usage as the shift gear set + drain punch is optimal to help against bulkier teams with blissey as a common special defense sponge. drain punch helps bypassing this pink blob.
excadrill: if you dont have a entry-hazard-setter, drill here can work wonders for setting up rocks and for removing them with rapid spin as well. excadrill in general is a nice common lead on ho-teams.
dragapult: dragon dance + 3 attacks is extremly powerful and the last slot can be even fire blast for the option to bypass ferrothorn, as iron barbs + rocky helmet is a huge damage against dragapult.
urshifu (fight/dark): either bulk up + 3 attacks with sucker and black glasses as an item or choice band-set with u-turn can be an optimal partner for necrozma.
volcarona: has many sets to abuse, but it depends on the team structure and what exactly you want, but commonly it runs either the offensive set with quiver dance and bug buzz, fiery dance and psychic, or a bulkier version with flamethrower and bug buzz + roost and sometimes safeguard to not get hindered by toxics and t-waves from chanseys and blisseys, so it can setup safely.
these are common teammates for necrozma, i hope the answer helped you to gain some input about this mon.
(sry that the answer is so long btw, forgive me!)