Seem like you team is magic based. Actually I find it hard to use Frey to clear PVE content due to her healing even after transcend heal 2 targets only. Her shield does not protect physical attack. I replaced her very early in game.
If you continue to use Frey as main heal, I kind of feel that your dps will need a lot of life steal. In fact, when I cleared ch 7, my team dps and/or cc characters have a lot of life steal. Yes, my team damage is not as high as many players but I still managed to clear ch 7 hell. My healer is like to keep my tank alive because I couldn’t get good gear for my tank.
If you don’t mind grind slowly, I anyhow mix team party LoL. I use character that I like, so physical and magic base mixed together. This definitely hurt damage a lot LoL.
It is very hard to get gears with so call perfect stats and I grind until very sian already. I played this game since it’s early day launch time till now. Vespa has up ch 8 difficulty by a lot. I couldn’t match mix a team to even get 3 star for normal last Boss in ch 8.
More grinding for gear again.....and I find dragon gear stats suck a lot! Why so many mp recovery stats and a lot of cc resist also. Even my tank can take hit but my dps are not killing fast enough. Usually the timer went out then Boss enrage and I got wiped....
Ummm I presume you play on and off? Hybrid teams are very discouraged, and it's quite clear that Vespa advocates to full magic or physical teams with WB1/2 and the new conquest boss plus Tyrfas.
You no longer need to spam lifesteal, in fact it's not worth to sacrifice too much dps stats for lifesteal. It's used a bonus now. Chapter 1 to 7 was greatly nerfed for chapter 8, and chapter 8 easy to hard were nerfed as well.
Frey's shield is good early game. If it gets destroyed after only awhile, you need to pump more attack to her. At end-game her shield is quite weak. Better off cheesing with Medi S1 or Loman S2. I do hate her single target heal tho. I'm pretty sure Frey's shield blocks any damage plus CC.
Gear grind has always been the main focus. Especially so with the new gear line and system for T7 and T8. But repositorium gives about 10 T6 4 option selectors for 10 repo clears, and T6 gears are not affected by the new system. There's also 2 option T8 gear selectors from dragon raid shop, which people usually use on Lava Gear.
BD80 and above was never meant to be soloed. Whales still bring 2 to 3 accounts. If you are using hybrid team, quite obvious that you will deal subpar damage...
Also, it's likely your Artemia survived longer because of her UW. I have a friend who mentioned that his whole team died (level 90 full T5) and a level 67 Artemia with UW was the last to die in BD80. 
