This is Ellen, a Glum Reaper + Lantern Ghost gal she's a pretty chill person until she has a job to do or fix... she's successfully reaped a goomba and it's belittling him... I think

Ellen: "D'aww, so sooooooory li'l dood... I wonder where you'll be sent to: The Overthere or Underwhere...?"

She laughed and puts the ghost goomba into the ground

Ellen: "Underwhere t'is then!! Hihi!"

Ellen noticed some people trying to revert the ghosts back to their normal selves, the was planning on what to don't to stop it from succeeding

Ellen: "Oh noooo... Am I sensing mortals undoing OUR hard work? Tsk tsk... not cool duuuuudes... guess s'up to me to fix that...~ brodio... hold my pickaxe scythe for moi?

Ellen throws her weapon at you, and you caught it

Ellen: "Now... wanna see me 'stroy them just as hard when i destroyed your heart when you 'fessed to me?? hihihihi... the memories, heh.... You couldn't sleep for days, and yous was sooooo devastated!