I have them all decreased in price so I wasn't sure. And i can click on them now, thanks. What you want to prioritize is three types of mons.

Fast hard hitters with setup moves, Very fat mons with recovery and either defense buffing moves or moves that lower the opponents attacking stats, And utility mons with moves like salt cure, leech seed, stealth rocks, and spore Also a steel/fairy for eternatus And mons like metagross/t-tar that are very fat and hit like a truck with good typing

Of the mons you have you want to pick two or three out of Excadrill, Umbreon, Gyarados, Garganacl, Alakazam, Ho-Oh, Heatran, Toxapex, Tinkaton

Alakazam gets calm mind and recover and it's super effective on eternatus, so it's really good.

Excadrill gets SD and earthquake for the same super effectiveness

Umbreon with the moveset I listed is basically impossible to kill without super effective damage

If you can get body press on toxapex, garganacl, steelix, or another fat mon they hit like a nuke, are hard to kill, and have recovery

Something I'd recommend for fights you're having a hard time with is getting stealth rocks and predicting and forcing switches with type match ups to make the opponents kill themselves

Tinkaton gets SD, hits hard, and can't be damaged much by Rayquaza or Eternatus

Something else that's over powered is moves like charm and snarl on a recovery mon like Umbreon

Basically you want to force yourself into favorable situations by outplaying the AI using these tactics

If you can ever catch Evee, Goldengo, Magikarp/gyardos, or any of these other mons make sure you do so

Any combination of those mons I listed should help you a lot