Bone Spear + Reach of the Dead

Can I use just 1 Thrall for casting Bone Spear after I use Reach of the Dead? Or do I need 2 Thralls that are close to each other, given that Bone Spear has a range of 10 feet.

Reach of the Dead

You channel your necrotic magic through a thrall, expending it in the process. If the next action you use is to Cast a Spell that has a range, you cast that spell from one of your thralls within 60 feet. That thrall becomes the point of origin for your spell. You calculate range and cover from their space instead of yours. The thrall is destroyed.

Bone Spear

You shape a thrall into a spear of jagged bone. Destroy one of your thralls, then make a melee spell attack roll against the AC of each creature in a 15-foot line from where the thrall was. The spear deals 1d8 piercing damage (or double damage on a critical hit). This spell counts as two attacks toward your multiple attack penalty, but the penalty doesn’t increase until you’ve made all the attacks.

I think the consensus is the second option, you need to pop two thralls.

I think the consensus is the second option, you need to pop two thralls.

That would be my read. Burning up a thrall is a component of each of those actions.

This is one of the reasons why I think Necro getting the option to skip the thrall attack to summon +1 thralls is a good idea.

IMO, the jump from 1 thrall to 2 thralls @ L7 is too big, and trading away the possibility of the cantrip to deal damage for that extra thrall would be a balanced way to really help the Necro's early game.

Needing 2 turns minimum for Bone Spear is bad enough that a lot of players who otherwise like the concept, may skip the spell because it's just not worth it.

I like the idea of optionally losing the attack on create thrall to gain an extra thrall. It could also help bonny barrage.
I had been think just giving some sort of action compression to the class early could help. Similar to the gunslinger and reloading. When you move, use certain types of skills, or casting from spell slots. The casting one may be too much. I just don't want every turn to be a choice between moving or creating a thrall.

As written, it can go either way - it comes down to where you read the spellcasting happening in Reach of the Dead.

"...you cast that spell from one of your thralls within 60 feet. That thrall becomes the point of origin for your spell. You calculate range and cover from their space instead of yours. The thrall is destroyed."

That reads to me as you cast the spell, then the thrall is destroyed. Which allows it to work, because Bone Spear has to finish casting before Reach of the Dead tries to destroy the thrall (and then fails). Of course, this is the kind of thing that feels like you're getting away with something, so I absolutely understand people reading it differently. I just think that it seems to be written clearly as first you cast the spell (and finish resolving it), then destroy the thrall.

Regardless, it's something to be cleaned up in the final book.

Edit: Actually, I think it presents a bit of a paradox the other way. Bone Spear's Target is the thrall, so if you don't have a thrall to destroy for it, you can't cast the spell. But if you can't cast the spell, Reach of the Dead won't destroy a thrall, right?