Champion of Ogremoch's Bane

Earth Glide. The elemental can burrow through nonmagical, unworked earth and stone. While doing so, the elemental doesn't disturb the material it moves through.

Siege Monster. The elemental deals double damage to objects and structures.

Ogremoch's Bane. The elemental is a creation of Ogremoch's Bane. It gains the following benefits:

• It gains a +2 to its AC due to Ogremoch's Bane keeping it shielded with its thick dust cloud (this is already reflected in the creature's AC.)
• It gains the ability to use Erupting Earth once per day.
• It wields a greatsword and gains the Poisonous Strike ability, reflecting the poisonous damage caused by Ogremoch's cloud entering the characters' wounds.

On initiative one, Ogremoch can utilize three abilities:

• Any creature within Ogremoch's Bane that can breathe must make a DC 11 Constitution Saving Throw. On a failure, the creature takes 1d6 poison damage. For each consecutive round the creature takes this damage, the damage increases by 1d6. Characters can hold their breath while in Ogremoch's Bane to avoid this effect, but must make a DC10 Constitution Saving Throw when taking damage to maintain holding their breath.
• Ogremoch's Bane can build a wall from floor to ceiling up to 10ft. in length.
• Ogremoch's Bane will corrupt any elemental within its area. Galeb duhrs summoned by the ritual at the Steadfast Stone take 5 rounds to be corrupted. On the Ogremoch's Bane's turn on the fifth round, the galeb duhr are corrupted and the ritual fails.

Ogremoch's Bane is impervious to all damage and spells except for those listed in the Out of the Abyss module.

Multiattack. The elemental makes two greatsword attacks.

Greatsword. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 14 (2d6 + 5) bludgeoning damage.

Poisonous Strikes (Recharge 6). The elemental uses Multiattack. Each attack that hits deals an extra 5 (1d10) poison damage.

Erupting Earth (1/day). The elemental chooses a point it can see on the ground within 120ft. A fountain of churned earth and stone erupts in a 20-foot cube centered on that point. Each creature in that area must make a DC12 Dexterity saving throw. A creature takes 3d12 bludgeoning damage on a failed save, or half as much damage on a successful one. Additionally, the ground in that area becomes difficult terrain until cleared. Each 5-foot-square portion of the area requires at least 1 minute to clear by hand.