a 5 star team that never dies?

He is clearly fighting against Cobra Kai team because... you know... Cobra Kai never dies. 

Probably a better idea to start reading kits rather than decrying how they work as BS.  

Quote from Iden's kit: If no other allies have the Leader tag, and all allies are non-Droid Imperial Troopers, Iden gains 100% Turn Meter at the start of each encounter, and whenever she is defeated she revives with 100% Health and Protection if there is another active Imperial Trooper ally.

Also, here's the buff she gives her team: We Adapt, Or Die: +30% Critical Chance, +30% Offense, and +30 Speed; revive with 70% Health when defeated; if dispelled, recover 80% Health, gain 80% Turn Meter, and can't be critically hit for 2 turns

She has a lot of revives. You need to dispel the buff, THEN defeat her allies, and then defeat her.

Cheating or your bad for not reading Iden's kit?  Have you ignored Conquest for the last few months?

Even if you didn't know or hadn't read the kit..................surely after the first one comes back you click on that strange green buff (adapt or die) you haven't seen before?

You're either trolling or massively mis-playing the game.

it was iden versio and stormtroopers.... they all came back after i killed them... imo its BS

She will die permanently on Dathomir missions in RotE TB, if you kill her when she has -100% speed. 

Nightsister Zombie can revive after being defeated at -100% Speed from Endless Horde. While a Nightsister ally is active, the first 2 times another Nightsister ally is defeated by an enemy attack, they are revived, recover 100% of Nightsister Zombie's Max Health and Nightsister Zombie is defeated.

not if she has undying sacrifice level 8 an omega ability  

it's  her second special (undying sacrifice) that keep her from dying from stack so long as there another NS alive.

it's not limited to pvp mode.

It’s really easy to explain actually.  Tons of teams have revive mechanics, just off the top of my head Nightsisters, Ewoks, Jawas, Bounty Hunters, Phoenix, Iden versio, Nute Gunray, Wat Tambor, Visas Marr…I’m sure there’s a bunch I’m forgetting.  It can be frustrating when you don’t have appropriate counters but be patient and learn from the experience.

Not in PvP game modes. This is true in Dathomir missions in RotE, but she won’t die in GAC / TW.