Haru - Raikou
"An autopsy, and a request."

Released in:
Version 3.3 - Beyond Elysium

Note that v3.3 also introduces Mia - Starchaser.
Both Mia and Haru are main-dps operatives, and they don't support each other.
As such each needs their own article, as they're basically unrelated in how they work. 

This article is about how Raikou affects the games meta. If you only want details on Raikou herself - how to play and build her, then view her article here.

Also: Raikou means "God of Thunder" in Japanese, by the way.
Which is nice and confusing, as Haru - Raikou doesn't deal Electric-damage, she deals Chaos-damage.