Charys/Chronology

Empowerment Arc
Ifrit managed to overpower Shizu's mask and rampaged around Rimuru's newly built village until he was eventually defeated and eaten by Rimuru.

Up until Demon Lord Awakening
Inside of Rimuru's stomach, he was saved by Veldora and became his conversation partner. They started commentating on the various happenings around Rimuru's life from inside his stomach and gradually bonded, becoming friends.

Hero Awakening Arc
At the behest of Veldora, Rimuru restored the fire elemental with a physical body, while Veldora granted him the name "Charys," based on the magical core of Charybdis his new body was created from. Through both the combination of his powerfully crafted physical body and the name he was granted, he evolves into a "Flame Lord", his strength now surpassing an unawakened demon lord. He then serves as Veldora's assistant within the Labyrinth.