Mage slayer vs Spellike abilities

[Demonic Doudou]

Hi,

Can Demons or any spellike using creature is affected by the Mage Slayer feat?

Thanks

 

[RUMBLETiGER]

Erm... Maybe.
Mage Slayer states, in part, "Spellcasters you threaten..." and so we need to define if monsters with Spell-like abilities are spellcasters.
The Glossary on Spellcasters defines them as, "A character capable of casting spells."
The Glossary on Spell-like abilities states, " Spell-like abilities are magical and work just like spells..." and so one could argue that they'd be affected like spells. Someone else can argue that while they are like spells, they are not spells, "...(though they are not spells and so have no verbal, somatic, material, focus, or XP components)."
If I were your DM I'd rule in favor of the feat working, check with your own DM.