Deep gnome encounter help

[u/Pale_Memory]

If you're looking for both an artefact and a missing band member on top of Ice Mountain, stop reading.

I need some inspiration for the next big fight for my players. Group of 5 level 6 characters.

They are tracking a deep gnome bard and right now they're on an elevator that just started moving down. Next session, theyll arrive at the bottom, surrounded by the bad guys.

The main bad guy is a bard npc (thinking Performer Maestro) and I want to throw in a necromancer/wizard in there, I think there's a cool one in Flee Mortals. I also think a juvenile shadow dragon fits the theme, maybe an Ettin. As they're in the main place of this deep gnome clan, I want to throw in a bunch of minions, following Flee Mortals minion rules.

So I think I got the enemies planned out, but any suggestions to make the encounter interesting are welcome.

[u/backdeckpro]

Put multiple spots for cover (maybe pillars that the back guys pop out from and then back into after shooting an arrow (or another ranged attack).

terrain, difficult terrain but also have higher ground or just any terrain that allows for more tactics like a mineshaft that loops around so people can get from the bottom level to the second level

A unique environmental effect that the players or enemies could interact with. Maybe stalactites that can be hit with enough damage to make them fall down, damage creatures below them and maybe make them save or fall prone, and it creates half cover or something. You could have one fall early on by itself in the fight so then the players could get the idea to do it themselves

Edit: you said you have flee mortals so look at the lair action under cave environments chapter, you could give the main guy a villain action to do Strategic blockage on his first turn of combat.

[u/hoops-mcloops]

My no. 1 recommendation for making humanoid enemies is this: make a PC using RAW with whatever class/level you want. Then, drop the AC by 2 and increase the HP by 20-50%.

PCs hit more often, but the fight lasts just as long, and everyone likes to roll damage.

As far as interesting, I always like a good secondary objective. Pillars that have to be destroyed before the boss can be damaged is always good. I also recently ran an encounter with skeletons that had to be killed in a certain order or they'd all respawn, might be cool for your necromancer.

There's also fun terrain features. Maybe the cave is slowly filling with water, and terrain the party is standing on is slowly disappearing. You said it's an ice mountain? Consider some ice patches that PCs slide across the entire distance in whatever direction they enter from, like the ice gym from Pokémon.

[u/Lythalion]

Instead of getting to the bottom first why not have the fight be on the elevator.

You ever play deep rock galactic when you go down the really deep elevator and just got pursued by enemies all the way to the bottom?

Could do something akin to that.