Me and a buddy just made the jump from Tier 2 to Tier 3 - we just whacked the Jelly King, alchemised our 4* gear (Ash Tail swagger, aw yeah), and finally got access to Emberlight. Wandered round being tourists, looking at the town's outcast Gremlins, good times.
Then we thought "Hey, let's take a peek into the Tier 3 levels now that we're here."
First Infernal Passage level wasn't so bad - sure, the monsters are a bit tougher and do more damage, but with careful play and frequent shield use that's survivable. The Ultra Capsules helped a lot too.
"Hey," we thought, "this isn't so bad. And what's that on the gate map - Stygian Steeds? Sounds interesting, let's try and check it out!" So we strolled onto the elevator, pretty sure that we had things under control.
And that, dear readers, is how we ended up lying beaten, broken and thoroughly humbled in the first Dark City mini-arena area while monsters trampled our corpses. Damn you, Kats. Damn you, Devilites.
Previously we'd had a pretty good system going, mainly sword and shield use (Calibur and Defender lines) with a bit of Graviton Bomb action from my esteemed associate. We'd take turns kiting enemies around while the other unleashed charge attacks in their midst. Tier 3 took our previously-successful tactics, rolled them up and spanked us with them. Hard.
My question is thus: How do you make the transition from Tier 2 to Tier 3?
What did we do wrong? What are vital things to take on a Tier 3 expedition? What's a good loadout, what are good tactics? How do you deal with hordes of foes whose every attack knocks off ludicrous amounts of health?
I find the Shivermist bomb to be far more effective in T3 than the Grav duo.
More generally, with T3 herding doesn't work nearly as well (imo). It's better to try and separate/pull one or two mobs from a group (kiting for a long time, if needed) and pick them off one by one.
You want to make sure you have a good coverage for the different foe resistances. Defense against elemental tends to be very helpful.
The biggest thing is just to SLOW DOWN. Rushing through T3 is something that people who have done endgame for a while can manage, but just starting out is very difficult.
You'll notice things get markedly less "unfair" when your gear is 5* and nearly maxed in heat. There are still some things that will be unfair though, like gremlin levels with mines/flamethrowers covering the map, and the always-dreaded quicksilvers.