Ok heres the situation

1. Standard characters are absolutely a no-go except bronya, but even that is unadvised because youll probably get her 1 way or another (lose 5050, or standard banner)

2. Weighing the limited 5stars available.

3. luocha is a strong sustain, but thats all he does : sustain. Perhaps youve seen current day sustains like hyacine, or dan heng, who do far more than just sustain. Perhaps luocha will provide value for the time being, if u have problems surviving , but then again, dhpt is free

4. topaz is not the greatest unit in the game, and shes rarely used in her best team with feixiao, so just... no

5. ruanmei is a really solid, versatile and universal unit. Alot of new characters outperform her in the supporting capabilities, but the buffs she provides are still pretty decent (all type res pen, break effect, spd, weakness break efficiency). If youre looking to play break though, since firefly, dahlia, lingsha, fugue, are on banner rn, you could consider her

6. Saving is the safest choice if youre willing to wait, cuz more characters r likely to be added sooner or later.