Ass. Wr. Wb.
Mas JD, how are you ? I think my interpretations of Kebal come from an aura Banten, spiritualists, society of penca Silat, tradition of Sudanese / ageman (Agama).
Debus is one of products maenpo in Banten West Java
Kebal is defense or could be attract too;
A means of protecting something from attack or
The action of defending from or resisting attack.
Kebal will be existing if you believe or NOT
A person or pesilat should be practice to build the ceremony retains an aura of mystery; quality that seems to surround and be generated by a person /pesilat / teacher / pendekar.
Wassalam
Kang Yana