Gun Magus Bounty hunter of mage criminals

[ThecrimeForceDragon]

Hey all.

I'm working on a level 7 Character who is going to hunt mages

I know there are no truly good mage slayers but I want to be much of a thorn in side as I can

I know I want to play a Magus with a gun who is an ex member of like a magical mafia / Farrell who got out but now wants to get his friend out

I am wondering how should I build him

Any thoughts besides x level of Eldritch archer

Also is spell cartridges worth it or should I go out fashion ammo

[Alphavoltario]

Arcana to keep an eye on for a 'mage slayer': Lingering Pain, Arcane Scent, Dispelling Strike.

You want to keep enemies from casting spells mostly, so hit them with continuous damage spells or pain effects.

Spell Cartridges is nice if your DM makes black powder hard to get. Force damage is a nice thing to just have on standby though, don't go for it strait away, since it's mostly useless until 5th level.

[Alphavoltario]

Also as a separate side thing the Witch Killer Slayer is made for hunting arcane spellcasters. It's literally the whole point of it.