Being extremely squishy and prone to interruptions, Klee requires good positioning or a shielder.
This is partially mitigated in her best teams, which currently focus on Overload with Chevreuse and provide strong stagger, helping Klee avoid getting hit. Even with this consideration, her best teams nomally don't include a shielder, she can often get knocked around and even KO'd in the midst of your rotations.
Running a shielder makes survivability with Klee more comfortable, but at the cost of total DPS. You can choose teammates depending on your level of skill and comfortability.
Klee has access to several animation cancels that let her deal damage with her talents faster than normal.
Her A1 grants Explosive Spark stacks when she uses Normal Attack, Skill, or Burst. When consumed, they give her Charged Attack extra DMG% and prevent them from consuming Stamina.
Hexerei effects give her up to 150% DMG to her Enhanced Charged Attack. This effect should always be active at max stacks.
Her optimal combos include in teams where Hexerei Resonance is active, or in teams where it is not.
Regarding Weapon Choices:
Rankings assume Hexerei Resonance is active.
Lost Prayer to the Sacred Winds: Assumes 12% DMG averaged.
Kagura's Verity: Assumes 2 stacks on the weapon passive.
Tulaytullah's Remembrance: Averages 25% Normal Attack DMG.
Surf's Up: Assumes dynamic stacking.
The Widsith: At [R5], this weapon performs closer to . Klee cannot reliably use the Elemental Mastery buff, should she acquire it.
Solar Pearl: At [R5], this weapon performs slightly worse than [R5].
Flowing Purity: Calculated with Bond of Life cleared. If paired with (4) at max stacks, this weapon can perform as well as .
Regarding Artifact Choices:
Sets
Lavawalker (4): Klee's kit makes it harder to utilize Vaporize and Melt the same way another Pyro carry would, but her constant Pyro application makes this set viable.
Echoes of an Offering (4): With a 50.2% proc chance on average that gives Flat DMG to her Normal Attacks, this set is competitive with (4) and easier to farm.
Desert Pavilion Chronicle (4): Klee naturally uses a Charged Attack early in the rotation, making this set viable.
Fragment of Harmonic Whimsy (4): This becomes Klee's second-best set when you are specifically using . For this reason, it's not recommended to farm this set specifically for Klee.
Substats
Energy Recharge: Prioritize until requirements are met.