lofty
峩 centers on the idea of towering height and steepness: something lofty, imposing, and precipitous like a high mountain peak.
峩 combines 山 (mountain) with 我, which likely contributes a phonetic element. The exact historical development is uncertain, but the mountain component clearly relates to the meaning of lofty or steep terrain.
A mountain (山) with a self-important ego (我) underneath: picture a mountain so tall and steep that it seems to boast about its own loftiness.
For ガ, imagine a gargantuan mountain towering above: gargantuan -> ガ, and the mountain's lofty peak scrapes the sky.