Noble Sacrifice

So I'm creating a setting in which artifice exists sort of in opposition to primal magic; ex: when Druid or Ranger spells are used around paving stones, the stones are overtaken by grass in addition to other effects, etc. 

The evil artificer villain's macguffin is a creepy surgical bay capable of synthesizing bodies into powerful zombies for his plan to take over the world. My main idea for a way to disable it: a primally powered character gives up their abilities, pouring everything they have into the "nature abhors tech" law, and each wire and tube and tank of liquid is torn apart by ivy, roots, and fungi, destroying the bay. 

Is this a good idea or is a character sacrificing themselves to depower the BBEG's big item too much of a trade-off?

I wouldn't feel great designing a campaign's plot in such a way that it requires one of my players to throw away everything their character has worked toward becoming. Character death - or something very near to it, like this - should happen organically, not be forced by the plot.

Bare minimum, the question of "how would you feel about a plot point that forces you to sacrifice your character or all of their achievements?" needs to be brought up in Session 0. 

The best approach I could see for this is for an NPC ally of the party - possibly a family member or mentor to one of the PCs - to make that sacrifice. It gets the job done and it also opens the door for a quest to somehow restore the NPC ally's powers somehow after the big bad is defeated.

Quote from ApplePaladin >>

I wouldn't feel great designing a campaign's plot in such a way that it requires one of my players to throw away everything their character has worked toward becoming. Character death - or something very near to it, like this - should happen organically, not be forced by the plot.

Bare minimum, the question of "how would you feel about a plot point that forces you to sacrifice your character or all of their achievements?" needs to be brought up in Session 0. 

The best approach I could see for this is for an NPC ally of the party - possibly a family member or mentor to one of the PCs - to make that sacrifice. It gets the job done and it also opens the door for a quest to somehow restore the NPC ally's powers somehow after the big bad is defeated.

 That could definitely work. If you have a DMPC, that’s even more heart wrenching for the party.

I get that. Right, using an NPC is probably a good idea. I have a separate NPC-breaking idea though, so either I wouldn't use both to avoid torturing that character or I would, and it would happen before they quite regain their abilities.

The sacrifice doesn't mean anything if you have pre-written it into the story. The whole benefit of D&D is that the choices of the player characters matter. The self-sacrifice can be one option, but it there should be alternative routes to success. Those alternative routes might be more dangerous, or might risk other consequences, but that's what makes the sacrifice mean something. 

E.g. in Harry Potter, Harry sacrificing himself to Voldemort would mean a whole lot less if it wasn't for the fact that his friends and family are telling him not to - that they will fight to Voldemort, that they will find another way.

If you really want to delve into that self-sacrifice moment, you have to build up to it and make sure the players are okay with it. And maybe it should be a last resort even in that case- like in the movies when a plan goes horribly wrong and a character dies to save the day-Iron Man in Endgame, etc. Some people would really enjoy a narrative arc like that and willingly throw their characters at the machine while laughing, whilst others will zealously guard their character's lives to the end. And of course, it requires actually having a nature-based character in the party (although i assume that, because this is being brought up, their is at least one). Communication with your players is key.