The greatest mage slayer build help.

[sflame56]

So I was looking around and the mage slayer feat has always been a super intriguing feat. You might not fight many mage users in your campaign but when you do they can be super hard to pin down and stop. I was wondering what is the build that can do in an turn a mage into a dude with a dagger just from the amount of dmg you pump into him. One idea was hexblade and monster slayer as a human variant with maybe fighter lvls stuck in. You start out with duel wielding or great weapon fighting and your job is to hex the mage then teleport to them using relentless hex which would be 7 warlock lvls. It would help make sure they never get away. You then get at least 11 into monster hunter to be able to essentially counter spell without using counterspell. Other option is going a full 15 into monster hunter to allow for more attacks on the mage. 2 fighter would allow for action surge. You essentially want to always be next to them while smacking them so many times that they can't hold any concentration since all of them will be at disadvantage. I want to play something like this in al.

Any ideas you guys have?

[Quoz]

Two objectives to lock down a caster: stop their ability to cast spells, and remove their ability to maneuver away from your countermeasures.

To stop casting, silence is the gold standard. Most spells require a somatic component. No speech, no spell. Blocking line of sight stuffs a lot of defensive options as well, and spells like fog cloud, darkness, and blindness all work to varying degrees but can also complicate things for your team as well. If you can get close and get surprise, open with a good old-fashion bag over the head.

To keep the caster from moving out of your no spell zone, you need to find things to drop move to zero. They also must work in whatever no casting settup you have on the caster. Grappling, the sentinel feat and a conquest paladin's fear aura are all good choices, but there are plenty of others.

Once you silence and isolate, a solid high-damage smack to break any held concentration spells and you should be good to go. The best part of this setup is than no single member of the party has to do all of it. If you have each only be good at one, nobody has to lose much in the way of effectiveness.

[Specter]

Unless you're starting at high levels, this build will be a pain. I'd go Bladesinger to level 6 to get Counterspell and Extra Attack, and then figure it out from there.

[Throne12]

I find that rogues make great mage slayer's. The feat mage slayer let's you attack if the spellcaster cast a spell while you are with in melee with it. So it won't be on you r turn. Which means you then can sneak attack again. And the way con works on spells. If your hitting a spell caster you what the hit to have more damage so the DC is too high. So my mage slayer would be level 10 because that's were most games get to.

Arcane trickser rogue 8/ divination wizard 2
V-human
Feats mage slayer, ritual caster
So firstly I'll have my mage hand casted and floating around then sneak up to a point I can see the caster. Then I'll send my mage hand to go pickpocket the caster of there Component pouch, spellbook, any and all spellcasting focus. Then ill cast Silence. Then next turn run up.

[tieren]

If you can get Yuan-ti pureblood, magic resistance is nice. If DM won't allow it I like forest gnome for the advantage on all mental spell saves.

Then I would want Oath of the ancients Paladin level 7 to get the magic resistance aura, also smite is a great damage boost for the concentration busting damage.

You need counterspell and a bunch of slots for it, the mage slayer feat doesn't let you interrupt casting so if you don't find a way to do that they can misty step away without letting you get that reaction attack (by the time the spell is cast they are no longer in range and no Opportunity Attack on a teleport)

[nickl_2000]

Monks are often considered the Gold standard for mage slayers. They get evasion at level 7 to avoid those AoE nukes, Diamond Soul at level 14 to be proficient on all saving throws (and can re-roll on fails with Ki).

A Shadow Monk can cast both darkness and silence with their Ki and they can move incredibly fast with Monk movement + bonus action dash with their Ki. Once they are next to the mage, they can pretty easily stun lock them and put the mage in a world of hurt.

[Ivor_The_Mad]

A ring of spell turning is nice and the ability to create an anti-magic field would be helpful...

[Easy_Lee]

One more option: Sorcerer (yes, really). Counterspell stops the enemy's spells from going off, and with the Subtle Metamagic enemy casters can't stop yours. Hold Person (wisdom), Banishment (charisma), and Blindness / Deafness (constitution) can specifically handicap the caster while your allies attack it. You'll want the Alert feat so that you can't be surprised and are always able to take reactions.

For the feat, rogues and monks are generally considered the best users. Both have strong mobility, stealth capabilities, and good opportunity attacks.

[Rogerdodger557]

Any fighter with the feat works as well. While you might not get the nova damage, you get more attacks per turn than any other class, and having to make several saves in a row at disadvantage is more than likely going to have make the caster lose concentration.

[Deathtongue]

If all I cared about was locking down casters while not being terrible at everything else, I'd put in at least three levels of Celestial Sorcerer at its base. You get Silence and, crucially, Subtle Spell and Quicken Spell.

Subtle Spell is a great trick for the anti-mage slayer. You get to:
1.) Cast spells while someone is in a Watery Sphere while they can't.
2.) Cast spells while someone is in a Silence spell while they can't.
3.) Dodging Counter-Counterspells.

Quicken Spell's utility is obvious. Putting up a Silence while using your regular action to do something else.

Seems like it'd be best to finish off the rest of the levels with Bard or Bladesinger. Alternatively, you could just be a Sorceradin of varying spell levels, but you miss out on Globe of Invulnerability -- which is VERY powerful caster shutdown.

[XmonkTad]

You need counterspell and a bunch of slots for it, the mage slayer feat doesn't let you interrupt casting so if you don't find a way to do that they can misty step away without letting you get that reaction attack (by the time the spell is cast they are no longer in range and no Opportunity Attack on a teleport)

This is why I recommend an abjurer. The best and most plentiful counterspells in the game. Not exactly what OP is looking for, but it is a good way of keeping casters shut down.

[Naanomi]

This is why I recommend an abjurer. The best and most plentiful counterspells in the game. Not exactly what OP is looking for, but it is a good way of keeping casters shut down.
At higher levels, Lore Bards beat them by just a little (in pure counterspell power)

The XGtE Monster Slayer Ranger Subclass has some neat anti-magic tricks as well

[holywhippet]

The XGtE Monster Slayer Ranger Subclass has some neat anti-magic tricks as well

Those are limited though. Magic user's nemesis allows wisdom save which most clerics and some wizards will likely pass and can only be used once before you need to take a rest (given most combats once might be enough though). Supernatural defense only works against saving throw spells, not attack spells.

Locking down a spell caster could be tricky even with silence, darkness/blindness and grappling. Especially if they are a sorcerer who can just bypass some of those limitations using subtle spell.