Rappas reason to fight is always boredom or childhood trauma, he fights because as a child he was force to. Now whenever he wants to fight out of a random moment , it was a flashback of "not being good enough". Tengai knows this and tries to help by telling him fighting will mostly be a no. He tries to get rappa to focus on calming activities but he's too broken to lean anything else. Just an uncontrollably nice and scare hidden child.
Two yelling and flashback)
You useless child!Rappas father yelled smashing a glass bottle. I HATE YOU I TRULY DO YOU CANT EVEN WIN A SIMPLE FIGHT! He said trowing rappa to the wall, you are the worst.
End of flashback: Rappa are you- FIGHT ME TENGAI RIGHT FVCKING NOW! Rappa no , calm down, let's go do something else hm? NO WAY , FIGHT ME NOW! Rappa I will never give up trying to help...
