I've been trying to whack together a build that forces enemies to attack you (Sentinel, plus 3 levels of Cavalier fighter), while also making it a bad idea to attack you (Armor of Agathys, Hellish Rebuke, Shadows of Moil).
Half Elf [Warlock 9/ Cavalier 4] seems to work pretty good. Blade Pact, Hexblade, Sentinel, HAM, EA + PAM. Bonus points if you have a friendly Cleric nearby to cast Warding Bond on you.
AoA gives you 25 temp HP and deals 25 damage to anyone that hits you. Shadows of Moil gives you advantage to hit (Tri-vantage thanks to EA feat) and disadvantage to be hit, plus it renders you immune to a ton of abilities (seeing as you cant be seen anymore), and it deals +2d8 necrotic to anyone that hits you.
Creatures you threaten have disadvantage to attack anyone other than you (and provoke an AoO and a special bonus action attack from you if they do so). They also provoke an Attack if they leave your reach, or when they enter it.
If they attack you (and you have Warding bond up) it's likely at disadvantage vs a high AC, and even if they hit, they take 25 cold damage (+2d8 necrotic) each time they do.