Cool boys nicknames

[JoMalones]

Hi
Our baby boy is a few days old but still nameless. I think he's pretty cool, as do his siblings, so would love to give him a cool name with a longer formal name.

So far have thought of Ace (Wallace or Horace), Rocky (Rocco or Rockwell). Still not totally in love with either so any suggestions welcome!

Otis - Oatie
Sebastian - Seb
Gabriel - Gabe
Osian - Ozzy
Robert - Bertie

Shouldn't nicknames evolve naturally?

I find some of the suggestions quite ugly personally, e.g. Woody (erection) or Oaty?

Why not choose a name, even a short one, you love as a standalone name?

Zed (zachary)
Jed (jeremy)

Ares (greek god of war) no nickname just thought it was cool