Thread:C319L/@comment-35770844-20180701080003

Firstly, similar buffs only stack if they are from different sources(boost atk from spheres, LS, BB/SBB and UBB all stack. BB and SBB are considered the same so they do not stack and the last buff remains. Selfish buffs, elemental buffs and normal buffs are considered different buffs and thus stack. Consider a mono-earth team with nagid, gyras and wannahon. Nagid provides all units with a def boost while wannahon gives an atk boost. Gyras then provides even more atk and def for earth units as his elemental buffs(+atk/def for earth units)

Next, there are some buffs that do not stack even if they are from different sources(from what I have read). E.g. first two turns boost(Muramasa and delusion device) Not sure about this but usually only affects FH and Arena

For damage, usually the units have +atk, BB damage, crit/spark/EWD damage, add hit counts, spark/crit/EWD vulnerability. They may also have double/triple attacking BB/SBB like the VA units or chance to attack again like Snow Miku. They are good to use on hard content to nuke the boss or to defeat them more quickly. By pairing them with defensive units, they can stay alive and help to whittle down the boss' HP(rather than a team of defensive team doing 1% damage every few turns). Defensive units tend to bulk up your team by boosting maxHP, def, or providing mitigation, shields, barriers. It may also extend to healers for some content which has damage reflect etc. Status ailment-units may also be considered a defensive unit if the opponent in vulnerable to atk down or injury.

For different trials, you will need to have a different combination of offense and defense. For example, Zevalhua's trial requires you to do certain %damage to cancel glorious which requires a more offensive team. Similarly, a more offensive team is needed to break Lucius' 300HP barrier(+hit counts), but the offensive buffs required for both are different and your units will have to have the right buffs with sufficient defense from your remaining units. On the other hand, Seria's SZ for example requires a much more defensive team and damage control is important to avoid having certain actions performed on the same turn etc. So each trial is different in its own ways and the team you need depends on the trial youre going for.

As for which units to raise to omni, Camila, Lumis, Kawab, Nagid, Hetepheres, Khepratum, Eerikki, Zelion and Ravenna are decent options, for a wide variety of uses like arena and questing.

For individual units and whether to raise them, I recommend going through the comment section of each unit's wikia page to see if the unit works well with a certain other unit. For instance, Luina has great chemistry with omni cardes and as their buffs do not coincide. There are also some youtubers who upload unit reviews and show off their abilities and recommended SP/sphere etc. that you can check out.

Btw, tridon's omni is said to be better than ultor from unit reviews but of course, go for ultor if you prefer him. Rift tokens can be earned every once in a while from the merit point system by defeating certain boses in frontier rift(no need to complete everything). Joining an active guild will help you to earn rift tokens during guild events as well as getting great units like elaina and grandt and their respective spheres.

Hope these were helpful to you:) 