>>20526502That's pretty standard.
Colosseum plays like a Nuzlocke, with the only exception that you can expect what Shadow is coming. Johto pokemon are shit, so there's a pretty selective mon pool. Having played the game multiple times, here's the mons I would call viable:
Espeon,
Umbreon
Hariyama
Typhlosion
Feraligatr
Quagsire
Ampharos
Furret
Noctowl (Only for Hypnosis)
Medicham
Hitmontop
Legendary Beasts
Stantler (Hypnosis again)
Forretress
Flygon
Heracross
All those are what I would call top/high tier in Colosseum, though you can always filll up with other funmons (I used Mantine and Misdreavus one run).
I like it a lot more than XD, because for one I think the story is more interesting, the admins are cooler, and the tougher pokemon selection forces you to make some interesting choices should you ever play more than once.