I like
Levi, it's a nice name that ages well and is easy to say and spell, but I do much prefer the similar name
Leon.
Levi just reminds me too much of the denim jeans and thus has a bit of a cowboy vibe to it as a result of that association. Although, I do think the possible anagram of 'Evil' and its similarity to Leviathan is pretty cool; a great name for a villainous character or pet snake!
I think
Sebastian goes best with
Levi as either a first or middle name:
Sebastian Levi or
Levi Sebastian.
Also, I think other names that end in -ian, -er, and -us tend to pair well with
Levi as first and/or middle names too such as
Adrian,
Damian,
Alexander,
Oliver,
Cyrus,
Rufus, etc.