fire
爟 centers on fire itself, likely as a bright, visible flame or a fire used for signaling or ritual purposes. The single given meaning 'fire' is broad, but the character's structure suggests a specific, perhaps ceremonial, fire.
爟 combines 火 (fire) with 雚, which likely contributes the sound. The character is associated with a signal fire or beacon, but the exact historical development is uncertain.
The left side is fire 火, and the right side 雚 looks like a heron or a watchful bird. Imagine a heron standing beside a bright signal fire, keeping watch.
For カン, picture a can of fuel being poured onto the signal fire: can -> カン, and the fire blazes up.