To DPR, In regards to the Death Penalty for captured Mercenaries.

To Donetsk People's Republic (DPR), beware of unforgiveness. It could prevent you from succeeding in your plan to fully liberate your people. You have been shown mercy by our CREATOR, time to reciprocate that to your fellow men.
I will advise you to forgive the mercenaries if they have asked for mercy and promised to be good people ... only CHRIST can make them good, by the way. .. So, if they want an easy/possible reformation from bad to good, they should surrender to CHRIST who's the LORD of Heaven & Earth. If they refuse, they could possibly be give light sentence in properly secured facility/facilities.
It's important to also mention that the Region should make sure they are qualified to kill captured mercenaries/fighters to avoid getting punished for not being qualified. By qualified I mean killing with clean hands.

*Just trying to make sure that nothing prevents the Republic from defeating their enemy. Russia or your sister (LPR) could be used instead, and that could mean leadership coming from both/either places(Russia and/or LPR) after your liberation by them.