Ruan Mei or Luocha from the free golden thingy in 3.7

Hi I just started playing recently and I'm planning to main Mydei forever (after I get him) since I've loved him so much even before playing that I'm wondering who I should choose from the free 5 star because I don't have a lot of characters for him.

The only characters (that can support him) I have are: Bronya, RMC, Pela, and Gallagher. All of which are still level 60 since I just started like last week. Some of you might suggest pulling for tribbie first but I can't handle the possibility that I'll lose 50/50 so I won't be pulling for a support before getting him, however I might pull Cipher if I get him if you guys think she's good with him.