shine
煥 centers on giving off light: shining brightly or radiating brilliance.
煥 combines 火 (fire) with 奐, which likely contributes the sound and the idea of brightness or spreading light.
Fire 火 on the left and 奐 on the right: picture a bright fire spreading its light outward, making everything shine.
For カン, imagine a can of fuel being poured onto the fire, making it shine even brighter: can -> カン.