@Boxy-0U0 can remix!

Abilty: Healing Sounds
After she stands next to a Toon long enough (6 sec), the Toon regains a heart. The process is 2x fast if they stand still. This can be done to multiple Toons at once.
Cooldown: 30 sec
Soumi herself has only 2 hearts.

"This Twisted has gotten overwhelmed with Ichor and loneliness, chasing other Toons and hope of finding her best friend."
Still haven't thought of her mechanics yet.

Perhaps her trinket is her boots, speeding you up for missing hearts.