I think Leizi will be a S1 and S2 merchant.
Her S1 is kinda insane, it oneshot the 20k HP 50 res elite Shaman of TW.

S2 has massive AoE range, 4 enemy multitarget, and does 3800*30 = 110k damage. This is an EX map which she destroyed in one skill.
This is pre-module Mlynar tier damage but with massive range, so she's a top 10 toon guaranteed, only thing that might cuck her a bit is no anti-air.