this mod sounds like it could be pretty fun, so..
gametype: team survivor(for round based gameplay as it would be best for this game mode)
1. players join server, if no one is on blue team, server auto picks a "counter"/"seeker" and moves them to blue, then locks blue team so no one else can join the team
2. players spawn without weapons, player on blue spawns, has only knife and with white screen unable to see anything(using flash effect) for x amount of seconds and is frozen in place.
3. blue player unfreezes and white screen fades, they then look for players, first player killed is stored in variable, and after all red players have been killed, that first player that was found is swapped with the current seeker. and it all begins again
this is kinda similar to the tag mode that some alphas thought about a couple years ago. tho my programming knowledge at the time was not quite what it is today.