Jax

Extremely similar in history and usage to Max:
✓ short form of a surname (Maxwell, Jackson)
✓ aforementioned surname was originally formatted as "[Name]'s [x]" (Mack's well, Jack's son)
✓ the plural became combined with the original name over time (Mack → Mack's → Max, Jack → Jack's → Jax)
✓ original name is slang for man (ex. Guy)

Combined meaning of “brave warrior” and “sent by god”, like someone said before: rooted in the traditional Ajax or Jonathan.

A fresh twist on the name combinations of Ajax (“brave warrior”) and Jonathan/Jack (“gift from God”).