I was thinking a fallen aasimar Hexblade 14/ grave cleric six with a shield and sword. I plan to be able to tank heal and do a decent amount of damage with spirt guardians and spiritual weapon, thirsting blade, eldritch smite, lifedrinker etc. Story wise he is sent by his god/patron to kill undead and people who need to continue into the afterlife while protecting heroes whose time hasn’t come. Any advice build wise.

I think a lot of people are gonna talk about how MAD  it is or your action economy. But this build just so flavorful. This probably the best lore cleric multiclass. I mean you switch out grave cleric for forge cleric. You could have had your best friend trapped in a different plane and the only way to bring him back is forging the best blade/armor ever to bring his spirit back. In the process his spirit got stuck in the blade/armor creating your patron. He could be messing with you the whole time that you have imprisoned a god your sword, just to get a laugh

We roll for stats (reroll pairs if there low) plus we get a free feat at level one regardless.

Really love the forge cleric idea and Hexblade specter could be you have enough power to bring him out of the weapon for bursts of time.

Yeah that is a really good idea