Yuumi

Don’t Get Too Attached

Lane harassment and consistent damage output.

Durability and crowd control

Guardian

Guard allies you cast spells on and those that are very nearby. If you or a guarded ally would take damage based on level, you're both granted a shield.
Demolish

Charge up a powerful attack against a tower while near it.
Bone Plating

After taking damage from an enemy champion, the next 3 spells or attacks you receive from them deal 30-60 (based on level) less damage.

Duration: 1.5s
Cooldown: 55s
Revitalize

Gain 5% Heal and Shield Power.

Heals and shields you cast or receive are 10% stronger on targets below 40% health.

Creative tools and rule bending

Biscuit Delivery

Gain a free Biscuit every 2 min, until 6 min. Consuming or selling a Biscuit permanently increases your max health and restores health.
Cosmic Insight

+18 Summoner Spell Haste
+10 Item Haste

Guardian is especially powerful on Yuumi thanks to your constant close proximity to teammates while attached with [W].

Demolish is an ideal rune choice for early game tower plate leads where you're able to pressure the enemy out of lane.

Yuumi has incredibly low base health so all forms of damage mitigation help immensely in keeping you alive.

Yuumi provides a considerable amount of shielding and healing from her passive, [E], and redemption combined with the burst shield from Guardian.

Biscuit Delivery further empowers your ability to sustain and bully in lane for early game tower plate gold.

Cosmic Insight's general utility is perfect for