Eithne lashes out with a radiant arrow deep from the void that destroys one of Mourne's duplicates as Troben sends an echo of himself to slash and destroy another. There are now "two" Mourne's out on the battlefield instead of four. Then Eithne unleashes thunder that causes the horrible lieutenant of the Plague Lord to shudder before it casts Misty Step and slips northward. "Protect me." it wheezes at the Dredge, which slips down to take up a defensive stance before Mourne. As the thing steps away from Baldric, the Paladin cuts in on the creature as it steps away, then follows with two more cuts.
The dwarf, Tiberion, steps toward Remy, "Me know'd, me know'd." he answers Baldric's admonition, grumbling. "A 'Thank ye, Tibby, now would ye be so kind as ta help me niece, Tibby' wouldn't hurt ye." Tiberion grumbles under his breath. The dwarf reaches out and touches Remy with a prayer and some of her wounds begin to mend.
Vrod swings wildly and misses with his first strike, but brings his ax in an overhead arc and drops it right through the middle of the Wretch before him, killing it. He then steps up to the other Wretch with wild eyes. He's not going to let it escape him without paying a price. As Vrod rushes at the Wretch, it moans hideously and strikes out at the barbarian, smashing him twice.
Feeling a bit better, Remy steps forward and rams the Dragon Lance twice into the gut of the massive Dredge.
"Oh no you don't, creepy." Austin growls as Mourn disappears and reappears near the giant behemoth. He rushes across the room and, overcoming the effect of the Sanctuary spell, launches a fire bolt (not sure which remaining dupe was actually Mourne and not wanting to 'waste resources, so to speak'), destroying the final duplicate.
"I should kill..." wheeze "You!" Mourne growls at Austin, "But you, my phantasm..." wheeze "wielding friend are most..." Yeah, you know it by now, "dangerous to my Lord." And with that, he launches a barrage of inerrant missiles at Troben.
Yeah, upcast of Magic Missiles at Troben... hahaha what a beautiful waste of an upcasted spell by Mourne! He almost couldn't have done less damage.
Looking over the RAW of Mirror Image and an internet search, it does seem that Shadeus' interpretation is correct. The second time Mourne was hit with a fireball, he lost his concentration and lost the spell BUT I'm an idiot and, just like Sanctuary, it is NOT a concentration spell!!! Well, I'm learning... apologies to you lot.
Troben was so close to hitting twice and getting a soft crit! :(
Protect: The Dredge can use its Reaction to protect an adjacent ally by imposing disadvantage on an attack made against that ally as the Protection Fighting Style (its massive chitinous arm is its 'shield'). It may do this twice as if it had two reactions but only once per attacker. So, if Troben attacks Mourne, the first attack is at Disadvantage but the rest are normal. If Baldric then Attacks Mourne, his first attack is also at Disadvantage, but the rest are normal. Any further attacks are 'normal'. This ability may only be used to impose Disadvantage against Melee Attacks. Further, if the attack rolls at disadvantage misses Mourne but would hit the Dredge's AC (even if its only one of the two rolls as if the better roll were not at disadvantage against the dredge), then the Dredge suffers the damage.
Terrain: The room is filled with thick viscera, slippery especially considering the softness of the ground. Whenever you move, you must make a DC 10 +1 per five foot space moved DEX Save or slip and fall prone. How much you fail determines in which space you fall.
Sadly, each of your enemies has feet with claws that grip into the terrain, nullifying this effect for them.
Eithne is currently flying and unaffected.
Dredge
AC: 15
Dex Save: -1, Initiative: +2
Special Abilities
A Stone Skin-like effect (resistance vs. all physical damage)
Protect: The Dredge can use its Reaction to protect an adjacent ally by imposing disadvantage on an attack made against that ally as the Protection Fighting Style (its massive chitinous arm is its 'shield'). It may do this twice as if it had two reactions but only once per attacker. So, if Troben attacks Mourne, the first attack is at Disadvantage but the rest are normal. If Baldric then Attacks Mourne, his first attack is also at Disadvantage, but the rest are normal. Any further attacks are 'normal'. This ability may only be used to impose Disadvantage against Melee Attacks. Further, if the attack rolls at disadvantage misses Mourne but would hit the Dredge's AC (even if its only one of the two rolls as if the better roll were not at disadvantage against the dredge), then the Dredge suffers the damage.
ATTACK
Claw/Slam: 2x attacks, +9, 1d6 +5 Slashing + STR Save against Knockback DC: 13. On fail by 1-3, KB 1 space +1d4 damage. FB 4-7 KB 2 spaces, 2d4 damage, and FB 8+ KB 3 spaces, 3d4 damage.
Wretch
AC: 16
Dex Save: +2, Initiative: +3
Slam Attack x2: +8, 2d6+4 bludgeoning damage, Reach 10 feet and has essentially the Polearm Master feat
Plague Fiend
Dex Save: +3, Initiative: +5
Special Abilities
Plague Rot: On any damage taken, roll 1d6. On a 1 or 2, the damage is halved due to chunks of rotten 'meat' falling off of the Plague Fiend where it was hurt.
Attacks
Attack: 2x claws; +13, 4d6+2 slashing damage
Mourne
Dex Save: +0, Initiative: +3
AC: 16
Special Abilities
Allies: Has the ability to make multiple enemies into allies in a 10 foot radius. Enemies get a DC 15 WIS save or believe Mourne to be their Ally, to the point of attacking their own true allies. If Mourne uses this ability on a character a second time, they gain advantage on the save. After that, the ability can no longer affect the target for a week.
Pre-sense: If Mourne makes an Ally of someone, he can sense through their sense while he concentrates on that ally (or former ally if the Allies ability has been broken) for up to 1 hour.
Jump: Mourne has the ability to 'jump' to one of his Mirror Images (if the spell is active), destroying that Image. Mourne can do this as a Reaction.
Multiple Concentration: Mourne has the ability to concentrate on at least 2 (possibly more, we don't know yet) spells/abilities at once.
Attacks
Spell Casting (spells so far; Sanctuary, Mirror Image) Save DC: 18
Summary
Vrod kills the Wretch and rolled two 1s on the ME roll... Eithne, why don't you roll to see what that comes up as? Thank goodness for the change to the house rule to let two 1s equal an ME because it seems like that's the only way we are getting them lately.
You guys are up.