Hey everyone, quick rules questions about a damage setup I'm trying to run.

I'm a level 7 Hexblade Warlock. Will the following scenario work as intended with these feat/spell setups?

My Turn 1: Cast Shadow of Moil on myself. Move to 15ft from my enemy. Pass.

Enemy Turn 1: Moves towards me to attack. Polearm Master triggers an AoO, I cast Eldritch Blast since I have Warcaster feat. 

My Turn 2: Presuming enemy is now 5ft from me after they tried to attack, I cast Booming Blade on them, followed by Polearm Master bonus action attack. Now, I move back 15ft and don't provoke an AoO since I can not be seen from Shadow of Moil. 

Enemy Turn 2: Moves towards me to attack again, triggering Booming Blade effect. Once they are within reach of me again, trigger my Polearm Master feat and I get another AoO.

Can I basically rinse and repeat this on each enemy? And does everything I'm mentioning in this scenario actually work as intended? Seems like a fun little combat setup for my Hexblade. Thanks in advance for any rules clarifications!

Some issues. First, if I had a player with PAM try to use their reaction attack with something other than the polearm, I’d say no. I can see a RAW reading where it doesn’t specifically say you have to make the attack with the polearm, but still no. Maybe your DM would allow it, ask them.

If you cast booming blade, you do not have the option to use your PAM bonus action attack. There the feat states you need to take the attack action with the polearm, but casting booming blade is not the attack action, it’s casting a spell which then includes an attack.

You would still provoke an OA. You can be attacked if you can’t be seen, just the attack would be at disadvantage. There may be some spells which couldn’t target you, but a melee attack can.

Thanks for the clarification. My assumption though is that I can use Eldritch Blast as my AoO attack since I have Warcaster. 

Warcaster feat:

• "When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature."

I've seen a lot of mixed responses with Shadow of Moil and whether it provokes opportunity attacks, since opportunity attacks can only be made on people you can see, and whether or not "heavily obscured" from SoM makes you visible to the enemy or not. 

Shadow of moil  makes you Heavily obscured to others, effectively suffering from the blinded condition when trying to see you, meaning you don't provoke opportunity attacks from such creature unless it can see you somehow. Whenever a creature within 10 feet of you hits you with an attack, the shadows lash out at that creature, dealing it 2d8 necrotic damage,

RAW i believe Polearm Master and War Caster works together but it may not be RAI. 

In my opinion, you could use Booming Blade + PAM + War Caster but only with a quarterstaff.

Booming Blade has a range of 5 feet, and the weapon that triggers the PAM feat at that range is the quarterstaff.

RAW also eldritch blast via War Caster must target the provoking creature with every beams attacks.

Booming Blade does not work with PAM bonus action for reasons stated in post #2. The rest of the OP seems to work ok.

Booming Blade does not work with PAM bonus action for reasons stated in post #2. The rest of the OP seems to work ok.

Sorry, I forgot to mention that the spear should also be valid for the combination Booming Blade + PAM + War Caster, not only the quarterstaff. The spear was included in the PAM feat in the 2018 errata for the PHB:

Polearm Master (p. 168). A second sentence has been added to the first benefit: “This attack uses the same ability modifier as the primary attack.” Both instances of “or quarterstaff” have been changed to “quarterstaff, or spear.” 

The only one that can use Booming Blade  and Poleam Master bonus attack is the Bladesinger.