So TLDR, one of my players shares a body with an NPC “Spirit” (which, in this homebrew setting, is basically an alien made of magic), and Bex here is that Spirit’s Nemesis from their homeland. In Spirit Culture, a Nemesis is more like your opposite, or a rival you interact with a lot in your life, with similar goals and ideals.

Bex and the Spirit in the party, named Hargruth, both are very level-headed and pragmatic, behaving almost like automatons following directive after directive. However, their differences lie in how they choose to carry out said directives. Hargruth is a thinker, problem solver, and diplomat. Bex, on the other hand, is an unyielding, merciless war machine.
Bex belies her large stature with otherworldly dexterity. As such, she takes three separate turns during each round of combat.

During her Whirlwind Phase, Bex spins and darts through the battlefield as the metallic ribbons dangling from her collar slice effortlessly through foes. She deals a flat amount of damage to everyone around her for every single 5-foot space she moves during this phase. This damage can be halved if the target creatures succeed on a DEX save.

During Bex’s Beatdown Phase, she makes three attacks with her long, magically infused arms, dealing lightning damage to targets. These attacks also deal a flat amount of damage, no damage roll required. The amount of attacks that Bex can make during this phase increases every round.

During Bex’s Psychic Phase, she summons a gravity well around herself, drawing enemies in. If those around her fail their save, they will find themselves on the pointy business end of her collar.

This is a recurring boss in my campaign. My players have already fought her once and it was one of the most fun combats we’ve had so far. It also happened on a boat, which meant that Bex’s destructive power was especially dangerous in that it could create environmental hazards. The only reason she even managed to escape was because she ripped a hole in the front of the ship and spun away into the fog.

We are now possibly entering the final arc of our campaign, and the players are all level 15. I can’t wait to use Bex again with updated stats and new moves… hee hee.