Common consensus is that Drakul put him in a parallel world, as Chandler recognised Drakul, Drakul recognised Chandler, and may have stashed him there for future interrogation about what he knows about him. Trying to turn him may have failed if Chandler is indeed is helping to develop countermeasures to that.
Drakul is an immortal or at the least ageless and very powerful, time may not mean the same to him ‘later’ may be a year or two, so Drakul can at his leisure retrieve Chandler and torture the info out of him, knowing no one in the WC can retrieve him.
Drakul could have killed Chandler outright, but didn’t either Chandler was an Ally or had information Drakul wanted. Putting him out of reach of the WC would suggest the latter.
