Special Equipment. Yuumi is attuned to the Book of Thresholds, a sentient magic item. While Yuumi sits on top of the book, she gains a flying speed of 30 feet (already included in her statistics). If Yuumi is within 5 feet of the book, she can use an action to cast the dimension door spell. She regains the ability to do so after finishing a long rest.

Bop 'n' Block. The first time on her turn that Yuumi deals damage to a hostile creature, she gains 29 (5d10 + 2) temporary hit points. If Yuumi is attached to her master as part of her You and Me! action, her master gains the temporary hit points instead.

Keen Smell. Yuumi has advantage on Wisdom (Perception) checks that rely on smell.

Familiar. Yuumi can serve another creature as a familiar, forming a telepathic bond with her willing master, provided that the master is a good or neutral-aligned creature. While the two are bonded, the master can sense what Yuumi senses as long as they are within 1 mile of each other. If her master causes her harm, Yuumi will end her service as a familiar, breaking the telepathic bond.

Prowling Projectile. Ranged Spell Attack: +4 to hit, range 60 ft., one target. Hit: 8 (2d6 + 2) force damage plus a creature hit with this attack is slowed until the start of Yuumi's next turn. If Yuumi is attached to her master as part of her You and Me! action, this attack automatically hits (identically to the magic missile spell, and can be blocked by a shield spell similarly).

You and Me! If Yuumi's master is within 30 feet of her, Yuumi can use her action to dash to them and "attach" herself, as a magical invisible tether bonds the two until Yuumi decides to end her attachment as an action. While attached, Yuumi floats in the ethereal plane, visible only to her master (and creatures who can see into the ethereal), directly at her masters side. Additionally, while she is attached, she is immune to all damage, cannot be targeted by spells or other magical effects, and cannot be attacked in any way.

Zoomies. Yuumi heals herself for 29 (6d8 + 2) hit points and grants herself the benefits of the haste spell until the start of her next turn (without the lethargy after it wears off). If Yuumi is attached to her master as part of her You and Me! action, her master restores the hit points and gains the benefits of the haste spell instead.

Final Chapter (Recharge 6). Yuumi sends out multiple waves of magical energy that are 20 feet wide and 40 feet long. All creatures (including her master if she is attached as part of her You and Me! action) she designates as allies heal for 38 (7d10) hit points (if a creature she designates as an ally already has all of their hit points, they instead gain temporary hit points equal to the amount rolled), and all creatures she designates as enemies must make a DC 13 Constitution saving throw, taking 38 (7d10)force damage and are restrained until the start of Yuumi's next turn on a failed save, or half as much damage and are not restrained on a successful one.