Immutable Form. The golem is immune to any spell or effect that would alter its form.
Magic Weapons. The golem's weapon attacks are magical.
Wear. As the golem takes damage, it begins to fall apart. Every time the golem takes 20 damage, it takes a point of wear. One point of wear imposes the following effect: -1 AC, -5 ft. movement speed (minimum 10 feet), -2 STR (this also gives -1 on the sword attack & damage rolls), -2 CON (this also makes the golem lose 20 HP. HP lost in this way do not contribute to wear)
Sword. Melee Weapon Attack: +13-x to hit, reach 10 ft., one target. Hit: 23 (3d10 + 7-x) slashing damage.
Fire Blast (Recharge 6). Fire erupts from the golems mouth. Makes 3 ranged attacks (+5 to hit). On a hit, the target takes 2d6 fire damage. On a turn where this ability recharges, the golem is immediately stunned until the start of its next turn.
I like pretty much the idea of an old rusty Iron Golem that is falling to pieces, but I think that 16 CR is a littel to much, with just a level 5 Warlock with Agonizing Blast and Repulsion Blast and a lot of patience you can take down this golem pretty easily
CR is too high for this monster. I'd put it around 11 I think. I would also removed the stun on the recharge of the Fire Blast. It only does 2d6 damage per projectile and recharges on a 6.
funny you bring that up. I actualy made a rusty iorn golem
also cr probably 2 high
make a way for it to remove it's wear