Alphys

Basics
Bacia is the royal scientist under most of the underground's rulers when she is alive. While having suicidal thoughts in all runs, she only acts on them in runs in which either Mettaton or Undyne have died but Sam does kill enough to trigger a genocide-like run.

Burst design
Like most of the main cast monsters, Alphys got a Starburst when the Gasters bursted. Hers are under both eyes and appear like lightning bolts. They glow yellow when she uses magic.