Okay then here is my endgame team I beat the league with last Monday.
First member is Sadie the Primarina, obviously my starter, and always the most over leveled of my team.
Second member and first Pokémon that I caught is not surprising, it's Zoroark which I nicknamed Trix. Unfortunately I didn't get use him as much as I would have liked to since he was pretty frail.
Third member is Fenris the Dusk Lycanroc, which is named after Fenris Wolf from Norse myth. Definitely a powerhouse, and pretty clutch since he managed to hit all of his Stone Edges against Kahului of the E4.
Fourth member was Lazagna the Totem Salazzle. As soon as I heard about getting a totem Salazzle in my Ultra Moon game, I was scouring every nook and cranny for those totem stickers. I managed to get my 50th sticker at Hano Beach, so I had this powerhouse for about half of the game.
Fifth Member was Verizon the Virizion. I actually have a funny story for this one. I was doing the Ultra Warp Ride for the first ever time during the main story, and ended up in a no-ring green wormhole my first run. This actually happened to be a Virizion, which I caught first turn in a quick ball. If that ain't lucky, then I have no idea what is.
My sixth and final team member was Nebby the Necrozma/Lunala fusion, or as I like to call it, Necroznala. I found Necrozma on Mount Lanakila, then got the N Solarizer and Lunarizer, then went to Mahalo Trail to catch Lunala and fused with Necrozma. This thing carried an INSANE Sp. Atk stat, rocking Photon Geyser, Psychic, X Scissor, and Moongeist Beam, this freak of nature was a force to be reckoned with.
So that was my team I beat the E4 with a week ago, on the 20th.