u/MiLiRu645

I am currently running a campaign with some friends, in a homebrew setting so obviously there is a lot of homebrew. One of the characters are a paladin, who is bound with a metal-spirit (Makes sense in lore, slightly recontextualized Magic system. A metal spirit is a living clump of metal) and I am currently building out the rules for this spirit.

Basic concept: The spirit the player is bound too can work as a kind of living armor, and the player can somewhat change its shape. If the player uses all of the spirit as armor, it has an ac of 20 (or maybe lower) However, the pc is paraplegic, and has to use some of the metal to create legbraces so they can walk, and also uses some of the metal to make themselves taller (since they're kind of a halfling) and also creates their weapons from the spirit. So they can have very high ac, but if they do they can't walk or really defend themselves. A bit like a tortle ig.

Currently I have the values set at

Base AC: 20

Legbraces cost: 2 ac

Being medium size height-wise: 2 ac

Creating a simple weapon or 5 arrows/other ammunition: 1 ac

Protecting another small or medium creature using the metal: 4 av

The player is a paladin, and should as such be at least kinda tanky with high ac, but I dont want it to end up unbalanced. The party starts at level three, and the player is currently considering oath of devotion or glory. Most of the typical "divinely appointed warrior" and such doesn't really apply to the system, but the function should remain similar. Any tips or help would be greatly appreciated, thanks in advance!