[KaijuUltraFan]

(I think?) It was mirroring what Leiha did, showing compassion to the enemy. I think he was trying to tell/show Belial that if he let the hate go he could maybe return to being an Ultraman and stop being a monster.

of course Belial was having nothing to do with that.

It was interesting to me that both Riku and Leiha showed compassion like that.