It's been many years since summons stop having Magic Skills - spells, that use spirit shots. Nowadays pets have only physical skills that use only soul shots.
Last servitor that used magic was Grim Reaper before GoD introduced class diversification. After that new pets were way more powerful and mage build on Wynn (pve) was superseded.
Trivia fact is that before GoD only Elemental Master was the only one who could benefit 100% from mage setup as Magnus the Unicorn was the only mage pet and it was A W E S O M E...........especially on 300 water weapon
https://l2wiki.com/Servitors