I think a game mode similar to marked for death from titanfall could be very cool, it’s been in a lot of fps games and is usually one of the more fun modes.

One person is constantly visible to the whole enemy team and the only way to score is by eliminating them, whoever is marked could always see the whole enemy team on radar when within range.

I think it would play great with portaling mechanics, I’m not sure what the vision is for ranked but it could even play well in ranked.