Question on cross save function

Sorry if this has been asked before, but I couldn’t find the answer. I have the Handsome Collection on XBOX One and the 360. I have two characters on the 360 and one on the One. I’d like to transfer the 360 characters to the one so I can trade some of the gear, but don’t want it to affect my XBOX One character. I won’t lose my character on the One or any progress if I do the transfer now , will I?

Nope. The only drawback is transfers must be done one at a time, and once a character is copied to the Xbox One, it’s there for as long as you want it to be, regardless of if you delete the original from the 360.