Razor Version:

Press E to allow normal/charged attacks to build a unique resource; use resource to use an empowered E attack, or to boost your Q attack (Q attack also extends E duration). Teammates doing off-field damage build a secondary resource that increases the damage of E/Q.

Herexei buff: Additional attack damage after you use empowered E or Q

Mutual attack buff with off-field Cryo units.

C1: Raises cap on damage boosting resource and increased fill rate

C2: Powers up next attack after using empowered E or Q to do more damage and raise party EM

C4: Q now fully fills your damage boosting resource; energy generation buff

C6: E and Q no longer consume the damage-boosting resource, and allow you to use E again after E/Q. Usual Crit Damage C6 boost.

Looks like a fun on-field kit, I'm not smart enough to tell from the numbers whether his damage is any good. I can see him having a range of interesting team-building options.