Most of the holy artifacts in Ylisse are designed to work for only one person, but there actually is something he could have gotten! The mastermind behind most of the bad stuff in FE:A has a unique tome of dark magic called 'Grima's Truth'.

Grima is a dragon the size of a mountain that is considered the god of all evil in Ylisse, and his fell power can animate and control the dead.

You know, in case you want Skeletor to have zombie minions or something.