In a forest clearing, you choose to send out the Legendary Pokémon Necrozma, who you've caught after a long and arduous trek through an alternate world - Ultra Megalopolis.

At the same time, you also release the Solgaleo gifted to you by the Ultra Recon Squad. Then, you raise the N-Solarizer that Colress gave you.

Necrozma and Solgaleo get pulled together and merge... The resulting fused Pokémon steps forward and roars, seeming ready to rampage. But your presence seems to calm it down.