What do you do with GHB and TT Free Heroes?

They are honestly just taking up space. I have 6 Narcians, 4 Clarises, 3 Navarre, Legion and masked Marths

I've only really used Masked Marth, Xander, and Camus. For me, the rest just sit there for a long time and are used as fodder, or just sent home. I understand they're limited units, but I know I'm never really going to use them so, there's not much point for me to hold onto them except for collection purposes.

I believe only Masked Mart 4* should be sent away, because she has no skills at all (and be frank with you, you won't be using 20k feathers to just to make a 5*+1). Legion is not bad either, and you can also use as a Fury 2 fodder. Narcian is a good fodder for savage blow and lancebreaker and so on. Don't be afraid to use SI, even if the target unit does not hahve the best IV, because merge allies will pass on all skills inherited and learned

I've actually put work into a decent number of them, I've invested in Clive, Masked Math, Michalis, Valter. I'm planning to 5* Camus (and probably Xander, maybe eventually) and would also like to work on Clarisse, but I've been too lazy to bother.

Everyone else is just chilling though