for starters, she was a cracked gem contained within a construct that managed to direct her will through said construct to the outside world
then she was a broken gem that managed to use her powers to make simulacrums of the crystal gems that could stand on par with them
and then, as a healed gem, she held back one of the oldest (that we know of) and most powerful (that we know of) gems in the series as one half of a fusion, exercising her particular powers during the fusion as well as her personal powers
Lapis is the most fragile-looking juggernaut that I have ever had the pleasure to be terrified by
she also had no body deformities but her eyes even though she had been cracked much more and for much, much longer than amethyst