Beware! Spoilers below, possibly not hidden!
This is all subjective and personal, and depends on playstile. I typically manage to do no grind runs (no Bai Ze or landworms grind at all), and still take absolute conqueror down with not much trouble. Picking decent leaders is the key. Now what makes the leader decent? Arts available and the final item set. Non-unique arts in the order of decreasing importance: Revives (Herbs, Remedies etc)->Wards->Hexes->Psi. Combat arts are available to any character, so they are not listed.
Typical setup usually includes one Cache+aoe union (ex: David-Zolean-Yuniver-Caedmon-Nora, Crossbow III; Gaebolg, Crimson flare, Cache, silence immunity, 2 healers - or even 3, if Nora manages to train lotions enough) and …Read more >
Some UA provide very high (empirically at least 90%, but less than 100%, suspect 99%, same as faleria or conquerors buff) evasion to the whole union while they are ready to go. It might be benefitical to fail triggers on purpose if said UA is below enemy in queue to dodge its attack before launching urs. Arts that DO benefit from this: all RWAs, both omnistrikes, phantom pain. Arts that DO NOT: summons (moot, since they resolve before anything else), conjurations, ex-machina, lughs revenge, thousand flowers, beowolf. To test: both assisted snowpetals, UAs on other Seven.Read more >