Guild Wars 2

Hi, I just bought the primeval armor skin and would like to know if this skin can be used multiple times or if I use it for example on a lvl 23 armor piece I will need a tramutation stone to keep having the same skin

Only once, transmutate to pass it along.

Yep. It’s either use T stones to transmute as you level or wait till level 80 and apply to your final exotic armor.