Gaster: @charanate
Sans: @noob4or5
Papyrus: @sanstheskeleton2011
Asgore: @amr192
Metaton: @dust_sans567
Toriel: @rubyssis12345
Nabstablook: @brokenbrook
Alphys: @all_-undertale
Undyne: @monsterbox09
So sorry: @cs2076320
Mad dummy: @cs1848589
Mad mew mew: @wbgaster
Chara: @firelilly2
Frisk: @rose_leadershipsoul11
Asriel/flowey: @frisk_thehuman5
Muffet: @gothsans3
Royal guard #1:
Royale guard #2:
Bravery: @sansglichtale
Justice:
Patience: @-genocidefrisk-
Perseverance: @theinevitableone
Kindness: @NOOTMAREISCHILL
Integrity:
Red: @dead_doll_maker
Euphoria/betty: @myaltacc_brockmccoy3
Temmie: @XxInkyInkSansxX
__----------extra news_-----------
No ocs until all roles are taken

And you can be different AU people after all Main roles are taken. You can be a undertale person and one oc/different AU person
You can have a role and be an oc or have a role and be 1 or 2 AU people