Warlock Patron Based on Fullmetal Alchemist [PEACH]

[Vogie]

While the Leaden Plating feature is simple one of its feature can not be applied to a Shillelagh weapon.

The feature specifies a nonmagical weapon you touch, while Shillelagh specifically states:

The wood of a club or quarterstaff you are holding is imbued with nature’s power. For the duration, you can use your spellcasting ability instead of Strength for the attack and damage rolls of melee attacks using that weapon, and the weapon’s damage die becomes a d8. The weapon also becomes magical, if it isn’t already

So it would only not work if you (somehow) were holding the weapon without touching it, were somehow able to cast Shillelagh on it (making it magical), then touch it.

Unless you were talking about another party member having a Shillelagh that you are trying to touch after a long rest.

I already give resistance to damage with the Molecular Manipulation feature, so that'd be a bit overkill