Our DM is doing a level 12 one shot where we automatically have access to all feats:
Setting and Racial restrictions are removed.
Can only take a feat once unless it says “You can select this feat multiple times.”
You still pick the ASI for a feat but don’t actually get the +1.
You do get a +2 ASI at class levels(4..).

Our DM is asking for our full builds ahead of time so he can attempt to balance the encounters.

What would you build?

I‘m not fully sure about tje details but take fighter and then the dragonmark feat that gives you access to CME and also the one that provides a spellslot fo your

Sorcerer with potent dragonmark, something with sleep for 4 hours, new no lock coffee build. Maybe pick up elven accuracy for easy superadvantage chromatic orbs. That leaves you one more feat for resilient wis/dex.

Sorry I guess I’m not making it clear. We just can pick as many feats as we want. There is no restriction. We just don’t get the ASI from them.

Genie Paladin 7, warlock 5 (fey for defense, fiend for offense) with pact of the blade. Elven accuracy. Dao’s crush gives restrained= triple advantage with your charisma based attacks. Maybe spell sniper so you can eldritch blast from melee.

Then take all of then. What is the question?

What build can utilize them all the best. I can take Great Weapon Master but there is no point if I don’t use a qualifying weapon.

Gloomstalker Ranger 5 / Sea Druid 7

Cold Caster, Faerie Trickster, Potent Dragonmark of Passage, Evocation, Divination, and Conjuration Adept, Warcaster, Resilient Con.

Use Cold Caster and Faerie Trickster to force enemies to fail Wrath of the Sea.

Fighter 1 / Vestige Warlock (War) 11

Familiar Friend, MI Cleric (Guidance, Healing Word), Magical Connoisseur (Bless, Warding Bond), Evocation Adept, Conjuration Adept, Abjuration Adept, Otherwordly Familiar, Warcaster, Resilient Wisdom, Potent Dragonmark of Passage

Use Warding Bond on your Vestige to give yourself resistance to all damage types. Go bonk stuff.

I think you should play a Gish cause you can get heavy armor mastery, all the boost in combat and all the spells from the adept and touch feats. The best Gish at level 12 is Warlock (3 attacks + smite). Bonus you can apply all familiar feats to your Imp

This is the way I am leaning. I am thinking I will use a Fractal Mascot as a Mount.

Take all of them and see if you can remember all the abilities and triggers! /s

You just 'get' every feat and a +2 ASI at L4/L8/L12 as well? Is your GM... insane?

He is very good at balancing as long as he knows the builds ahead of time. We are always honest about what we want to do because as long as we are honest he usually will say yes. He only says No to things if we try and pull a fast one.