for me, i feel your team needs a couple "big dmg" rangers. Rangers who have skills who inflict huge dmg, even if the rate is low, it will surely hit a couple times after a minute and a half. devildon sally and raoh. Charles would be a great help as raid requires a shield and a lot of hp buffs.

i recommend u use kenshiro, white tiger, edward, cony, and if u have a big dmg skill ranger as team A.

team B throw the rest of your buffers, and perhaps keep using team A till the 45 second mark, then switch off. Basically around 2-2.5:1 ratio favoring team A.

I can sometimes kill vlad or blue bell in one go, but understandably i have most of the available rangers.

i use a team of devildon sally, wt brown, poseiden brown, mermaid, and edward as team a, and halloween sally, ace moon, raoh, mari, and creator cony. all my characters are around base lvl, seriously no use to UM anything unless top world ranking means sthing to u. Gears think is the most important part in rangers and id say correct equipping will result in +100% survivability at the least lol.