Thoughts on my fighter/warlock/paladin high save Mage slayer.

[Hohadonc]

Starting stats
13 8 9 14 13 15
Core human
14 9 10 15 14 16
12 levels samurai
1 level hexblade
7 levels oath of ancients
Asi
+2 cha
+2 cha
+2 strength
Mage slayer
Resilient dexterity
Final stats
16 10 10 16 12 20
Saves are
+14 +11 +11 +8 +12 + 10
As well as resistance to spell damage and advantage on the saving throws against saves if within 5ft of the caster.

[DarkKnightJin]

You could probably get similar effects from just Ancients Pally. Which gets the Advantage on saves with either a Holy Avenger or a Spellguard Shield.
Without having to be within 5 feet of the caster.

You can add Hexblade for SAD if you really want, but I don't think it's really necessary.
You'd likely want 2 levels for Agonizing Blast, if you're already dipping.

[Talionis]

There are a lot of magical items that enhance Strength. You aren't going to be able to max Strength and Charisma easily if at all. You may want to give up on your strength and ask your DM to quest for magical item that boosts your strength. This helps in MAD builds like this.

Otherwise, I would advise Warlock dip to get Hexblade or Tomelock 3 levels and use a Shillelagh (Druid Cantrip changed to be keyed off Charisma by Tomelock), so you can be fairly SAD on Charisma.

[Grear Bylls]

As a general rule 21st level characters beat other 20th level characters. Might want to check that.

[CTurbo]

Aside from the 21 levels, I don't see the appeal for this character. This type of character would not live to see high levels with a 10 Con anyway.

Paladin 6/Monk 14 would do this much better but would be a bit MAD. You could start 8 Str, 16 Dex, 14 Con, 8 Int, 13 Wis, 16 Cha and end with 20 Dex and 20 Cha. You're proficient in all saves and also add +5 to them.

[Hohadonc]

Thanks for the response.

I made an error and it should have been fighter 12, but that does not significantly change things. All that is lost is a second use of indomitable.

I generally build assuming magic items will either not be available or you cannot rely on getting a specific one.

I looked into paladin6/monk 12 and while you do get slightly higher saves you lose both the resistance to spell damage and will certainly suffer from a drop from the 21 ac that this build can obtain.

On the health front it does suffer, but it stays ahead of a monk with a con of 12 and if it is a significant worry for someone you can take an asi in con or tough instead of Mage slayer.
Or if it is still an issue switch con and int around and accept a low int save of +5.

[Malifice]

Thanks for the response.

I made an error and it should have been fighter 12, but that does not significantly change things. All that is lost is a second use of indomitable.

I generally build assuming magic items will either not be available or you cannot rely on getting a specific one.

I looked into paladin6/monk 12 and while you do get slightly higher saves you lose both the resistance to spell damage and will certainly suffer from a drop from the 21 ac that this build can obtain.

On the health front it does suffer, but it stays ahead of a monk with a con of 12 and if it is a significant worry for someone you can take an asi in con or tough instead of Mage slayer.
Or if it is still an issue switch con and int around and accept a low int save of +5.

How many characters have you played to 20th level?

If the answer is (as I assume) none, why create 20 level 'builds'?

Start with a character concept (a renegade Thayan knight, with a latent gift for Sorcery that was discovered and exiled. He now covers his tattoos, and has sworn an Oath against Thay and their wizards) and then flesh it out mechanically from there.

Youre creating a character, not a 'build'.

[Cwyll]

What does the character look like at levels 5, 10 and 15.
Gives us an idea of your progression through the 'normal' game...

[Hohadonc]

The only Campaign I have played in that did not use pre-generated characters is currently level 17 and will likely get to 20 in 2-3 months.

I have played 2 characters over the course of that campaign and have built them from different directions. The first I wrote the character, then created the build. The second I decided on what I wanted to be able to do and built the build forming the character details around the existent build.

The level order would probably look something like
4 fighter
1 Hexblade
3 fighter
2 Paladin
4 Fighter
4 Paladin
Though the interweave of paladin and fighter after level 5 are flexible.

So level 5 Fighter 4 / Warlock 1
Level 10 Fighter 7 / Warlock 1 / Paladin 2
Level 15 Fighter 11 / Warlock 1 / Paladin 3