Champaran HumSafar Express : इन अजनबी सी राहों में, जो तू मेरा हमसफ़र हो जाये, बीत जाए पल भर में ये वक़्त, और हसीन सफ़र हो जाये. - Piyush Singh

Yes..it goes via Non Electrified delta route.
But more shocking thing earlier used to happen was,
BBS to VSKP: 1 Electric loco
VSKP-RJY : Another Electric Loco
and then RJY-SC : Diesel.
But...
more...

now ECoR have provided direct BBS to RJY electric loco which all the time stays with the rake even when the rake is idle at BBS yard (sometimes idling at Mancheswar or Barang also) like a Dedicated electric loco which will take the rake from RJY to BBS and then again bring it back from BBS to RJY next morning.