Something isn't right here!

My level 81 Infamous Swiftblade is 15D worth of gear is unable to survive a Tier 11 Map (From being able to face melt/tank Tier 15+ NO DEATHS!)

BUT

My Level 81 Infamous Sniper with NO RES - CRAP GEAR - DOES NOT DIE - DOES NOT TAKE DAMAGE - What the heck is going on here - I'm so upset!!

My entire build revolved around my swiftblade merc - Why did they need to do this?!

Did they just hot fix this or did they just gut certain mercs?!