I think Watcherwings could be named just cool stuff (Example: Xelqua, Xisuma) or magical type things (Lucid, Amulet). Those will probably be cannon (By cannon I mean characters I made) characters, so I'll try my best to give names that won't be cannon.

Charm

Crystal

Elixir 

Lotus 

Medicine

Rune

Potion

Galactic 

Xanadu

Obsidian 

Bedrock

Endstone

Portal

Ability 

Mask 

Abyss

Void

Xola

Lunar

Xannon

That's it. I couldn't find anymore- (I just searched up 'magical stuff' and 'gender neutral names that start with x' so here we are) Please suggest more, I'm terrible at names-