You shouldn’t fight a hard counter to a team with the team it hard counters..
That being said, I personally use JKR, GMY, Jolee, Han and Chewie to take care of those GG nuke teams while climbing everyday. And no, none of them are G13 and thus no relics. The mechanics of Chewie and JKR alone are enough to capitalize on GG’s massive health pool and marked mechanics + ignoring taunts respectively.
There’s no point in fighting them with a SE line up when you can just switch to whatever you need in order to climb in arena.
As for them nerfing EP so it couldn’t beat SE, that’s not really what happened. They didn’t nerf EP, they buffed MALAK because EP was able to destroy the most overpowered cash grab character in the game at the time. Darth Revan with no Malak can still very much be beaten by EP. The turn meter gain engine is only stopped by Malak’s kit.