Lt. Cmdr Worf...

Khan...

Khan(Star Trek Into Darkness) has blasted his way into the klingon high council room.. Most of the klingon's are badly wounded. Prior to passing out , Worf's brother Kurn contacts him on the Enterprise. Using site to site transporter, Worf(ST:TNG, ST😄S9, ST:TNG FILMS)Khan has has materialized in front of Khan.

Khan
Ah, so you're Starfleet's greatest warrior

Worf
Perhaps, today is a good day to die

Khan has his rifle from Into Darkness and he also has a sword made of the same material as a bat'leth.. Worf has his standard phaser and his favorite weapon, the mek'leth.. plenty of cover for both contestants if they so choose..
This is to the death. Also if both contestants lose their weapons then they can pick up a bat'leth as plenty of them are laying on the ground..