The name reached its all-time peak in 2021 with 18 births ranking #5182. FALLING Recent data shows the name is currently falling.
Elis is a clear variant of Elias rather than a loose multi-tradition modern name. The live source places it specifically in Swedish use and also notes it as a medieval English form.
That gives Elis a much firmer historical line than the earlier wider wording suggested. It belongs to the broad Elijah and Elias family, but with its own compact Scandinavian and historical English shape.