Yuumi is a unique support who attaches to an ally, becoming untargetable while casting spells. This grants her low personal risk and consistent ally support, but at the cost of individual vision control and roaming potential.
Yuumi's effectiveness is heavily reliant on her allied ADC's skill and game sense. She excels with strong, carry-oriented ADCs, synergizing powerfully to significantly boost the entire team's combat potential, especially in the late game.
While Yuumi often struggles with vision and roaming in lower tiers, skilled players must minimize risks, read the map, and contribute to vision where possible. Maximizing her late-game utility through strong coordination with allies is key.