Immutable Form. The Abyssal Crusader is immune to spells and effects that would alter its form.

Magical Resistance. The Abyssal Crusader has advantage against spells and other magical effects.

Relentless. The Abyssal Crusader doesn't need to breath, drink, eat, or sleep and can't be forced to do so by spells or other effects.

Siege Monster. The Abyssal Crusader deals double damage to objects and structures.

Titan Slayer. The Abyssal Crusader's weapon attacks bypass resistances.

Sharpshooter. Siege Breaker variant trait only. 

• The Siege Slayer's ranged attacks ignore half cover and three-quarters cover.
• When the Siege Slayer makes an attack at long range, it no longer gets disadvantage.
• When the Siege Slayer makes an attack with a ranged weapon, it can subtract five from the attack roll and, if it hits, deal +10 damage.

Multiattack The Abyssal Crusader makes three melee attacks with its glaive.

Glaive Melee Weapon Attack: +14 to hit, reach 15 ft., 1 target. Hit: 21 (2d10 + 8) slashing damage plus 11 (2d10) necrotic damage. The Abyssal Crusader restores a number of hit points equal to half the damage rounded up.

Siphon Soul Ranged Magical Attack:  range 250 ft., 1 target. Target creature takes 8d6 necrotic damage and must succeed on a CON saving throw (DC 20) or take twice the damage. The Abyssal Crusader restores health equal to the damage dealt.

Haze of Unlife (recharge 5-6). The Abyssal Crusader can use a bonus action to release a haze of demonic energy in a 30 foot circle, centered on itself. Each creature, except for Chaotic Evil creatures, must succeed a DC 20 Constitution saving throw or have their strength lowered by 2d4 points. A creature who's strength is lowered to 0 dies. A creature who has their strength lowered this way can only regain their strength with the Remove Curse spell or another similar spell or ability.

Raise Dark Soul. The Abyssal Crusader can use a bonus action to revive a creature who's strength was reduced to 0, except it is now an undead creature and its alignment is Chaotic Evil. They retain their current gear, stats, and abilities. Creatures revived this way are enslaved to the Abyssal Crusader until it dies, they die, or they are dismissed by the Abyssal Crusader.

Sentinel. Non-variant only. When an enemy creature enters the Abyssal Crusader's melee range, the Abyssal Crusader can use its reaction to make a melee attack against that creature. If the attack is successful, the creature's movement speed is reduced to 0.