She is a bit of a hard counter to Perdita due to stacking vent steam.
I tend to run Langston, then Iwould look at the effigy cause I finally have it and it is great for giving Mei more burning, oh and jumping on.
Emberling is a great little schemet for 3ss incorporeal.
Firestarter or Cassandra can give some more speed and schemey options. Ss miner can help here as well.
I tend to always pick arcane reservoir on her, then seismic and/or Vapormancy and sieze the day.
Joss is of course a great option as well.