Notes:

Asriel is Lincoln (so I guess this means Flowey is also Lincoln, lmao)
Toriel is Lori (she'd still be Asriel's mom in this, I believe)
Papyrus is Leni
Mettaton is Luna (hey, I just think it fits.)
Sans is Luan (this one was a no-brainer)
Undyne is Lynn
Napstablook is Lucy
Chara is Lola
Frisk is Lana (yes, I know frisk is in Lola's spot and chara is in lana's, I made this before I decided that frisk is Lana and chara is Lola)
Alphys is Lisa (duh!)
and Temmie is Lily.
Asgore is Bobby
Dogamy and Dogaressa are Mr. and Mrs. Loud
Muffet is Ronnie Anne
Monster Kid is Clyde
Royal Guard 1 and Royal Guard 2 are Clyde's dads