Welcome, here you get to know to beat the final bosses.  I hope this will be useful.
 

Final Fantasy 4

 Zemus/Zeromus
 

Final Fantasy 5

 Exdeath/NeoExdeath
 

Final Fantasy 6

 AtmaWeapon

 Final Kefka
 

Chrono Trigger

 Lavos
 

That's all there is here, go  back now.