Tyana Pass - Mirror Defense needs a touch up. Simple tweaks will go a long way.

[ShortbusGangster]

Mirror Defense feels like microwave minutes. I've gone hours in Defense and Survival, but Mirror Defense has a way of making time feel extremely slow.

It also hard fails you out of the mission if a rogue bomb one hits the objective. The Shard powers the tunnel right? So fail out that "wave", no loot or whatever, and force extract. There's no reason your prior completions should be void! Those rogue one taps start to happen around Wave 7+ because the crystal's hp doesn't scale with the enemies. 

Collecting fragments, 50/50 should knock 15-45s off the defense time. Helps to speed it up. 
And away with this hard fail nonsense. There's too much at risk. 
Crystal HP should scale by wave, but I'll take the first two and enjoy the game mode. 

[balckillofdeath]

dude, i have to ask are you playing steel path or regular?
why do you not bring a defensive frame? Limbo,frost gara to the mix