supremacy, leadership
霸 centers on dominant authority: holding supremacy or leadership over others, often through power or influence.
霸 is the older form of 覇. It combines 雨 (rain) with 䩗, which likely contributed the sound and relates to leather or covering, but the exact historical development is uncertain.
Rain 雨 pours down over a leather-like shape 䩗, like a leader's canopy dominating the scene. The top covers everything below, symbolizing supremacy.
For ハ, imagine a haughty laugh from a supreme leader under the rain canopy: ha -> ハ, and the laugh echoes their dominance.