Overview
Kolibri is a non-standard buffing HG.
Kolibri applies buffs depending on how long you wait before activating her Skill. When fulfilling her passive formation requirement, she can either apply Damage buffs at the very start of battle or apply both Damage and Rate of Fire buffs at the standard 6 second timing. Waiting for the Crit Rate buffs is generally not recommended. Overall, Kolibri has great tiles and an especially strong Skill if you can satisfy her position requirements for either the early Damage buff or both Damage and Rate of Fire buffs at 6s. That said, you may need to manually activate her Skill to make the most of her, such as if you are using her in generic echelons as a regular position 2 buffer. In such cases, P22 or Rex Zero 1 are often preferred as more convenient options.
As such, Kolibri is a slightly niche but recommended HG.