Ferrous Mk III - 4e and 5e Comparison

So, Ferrous Mk III, is the (?) faithful sidekick to Ormid, Veteran and Llewellyn. The third version, if you recall, was imbued with the essence of a chaotic dimension using the planar device found in the ancient Guild Vault, and as such, he is imbued with darkling powers. We are playing the Ormid games in 5e now, and tonight I converted him over. For your consideration then are his 4th Edition and 5th Edition stats, so you can see how I have converted him over. 

Ferrous Mk III
Large Construct (Chaotic [Evil])
Armour Class: 19 (Armour Plating)
Hit Points
: 85 (9d10+36)
Speed 30'; Dark Walk
STR 21 (+5) DEX 15 (+2) CON 19 (+4) INT 5 (-3) WIS 10 (+0) CHA 7 (-2)
Saving Throws: Constitution +7
Damage Resistances: Cold, Necrotic, Thunder; Fortification 50%
Condition Immunities: disease, exhausted, frightened, unconscious, poisoned
Senses: Darkvision 60', Passive Perception +13
Challenge: 8 (3,900 XP)
Consume the Fallen: The defender inflicts +5 (2d4) damage to a prone enemy

Chaotic Soul: There is a cumulative 1% chance per round of combat that Ferrous' chaotic soul comes to the fore, and he goes into a rage. Whilst in this state, no one is considered his ally, and he will attack random targets to the best of his ability. He can be calmed with a contested Charisma (Diplomacy) check made against his Wisdom. Doing this is an Action.  Otherwise, he calms once all other creatures are slain, or after 3d20 minutes.

Fortification: Ferrous has a 50% chance to reduce any critical hit scored against him to a normal hit.

Murderous Presence: Whilst in the Murderous Presence stance, Ferrous inflicts +5 thunder damage with all his attack, as do all allies as long as they remain within 10' of him. All attacks by Ferrous and his allies also gain the following property; Crit: target is stunned unless they make a D.C. 13 Constitution save (save ends).

Multiattack: Ferrous makes two Pandaemonic Bite attacks. 

Murderous Presence: Ferrous activates his Murderous Presence stance. The stance remains active until Ferrous ends it (bonus action) is incapacitated, or the battle ends, whichever happens first. 

Pandaemonic Bite: Melee weapon attack, Reach 5', +8 to hit, one target, Hit: 18 (3d8+5) piercing damage and Ferrous teleports up to 20'. Even Hit: Target's armour (if any) is reduced by 2 until the end of Ferrous' next turn.

Winds of Madness: (Recharge 5-6): Range 50', Target suffers 40 (9d8) thunder damage and enemies have advantage on attack rolls against them until the end of Ferrous' next turn. If they make a D.C. 15 Dexterity save, the damage is halved and they do not grant advantage. Save Failed 5+: Target is pushed 1d4x5', and must make a second D.C. 15 Dexterity save or be knocked prone.

Wounding Bite: Melee weapon attack, Reach 5', +8 to hit, one target, Hit: 18 (3d8+5) piercing damage plus 18 (4d8) necrotic damage. Target must make a D.C. 15 Constitution save or suffer 18 (4d8) necrotic damage at the start of each of their turns, though they may repeat the save at the end of their turns to negate this effect. Save Failed 5+: If the target fails the initial saving throw by 5 or more, they gain Resistance to all healing spells and effects until they are no longer suffering necrotic damage at the start of their turns.


Dark Walk: Ferrous teleports up to 30', and gains total concealment until the end of his next turn.