Here how to bring and kill Baium at 13th floor alone and not with his co-fighters (not dying angels).
You must first complete the quest for baium which starts at Aden,Dark elf Guild.
Then you go at TOI 14 FLoor.You talk to the crystal and you enter Baium Room.
You wake up Baium,He kills you(1 hit for sacrifice)and you go to village.
Then you teleport at TOI 13 floor.Walk up the stairs and use command '/target Baium'.
Then you hit him and run down the stairs.
After some seconds it will appear at 13 floor next to you.His making dmg will be rly Low and His HP also rly Low.
Now you can solo Baium and take his Ring for reward!
Of course lowing his dmg and HP depends on the server you are IN.
Some servers have fought that Bug and the only you can do is bring him down.

i have try it, but i think it's not working

Will it work on c4 servers??????????(like l2elite)??

maybe works on celes c5?