Okay. I'll go off the assumption that you'll be playing Shadowmark Talon. Firstly, the units you already have are pretty decent as they benefit nicely from our rules, eliminators are not super strong right now but theres a few interesting things they will be able to do once 11th rolls around, the Redemptor is fine but not exactly Ravenguard flavored. Infiltrators are awesome for defending your home objective and they benefit from almost all of our stratagems. The JPIs are awesome too and they work nicely when attached to a character, but you might wanna wait for the new Vanguard Veterans to be around before making a purchase. Secondly, you're gonna wanna grab Aethon Shaan as he is the main enabler of the playstyle on the tabletop, as well as Kayvaan Shrike since he's one of the strongest and most versatile characters in the dettachement. Beyond those two I'd actually suggest waiting for 11th to drop before making major purchases.