GoodGuyGlen said:

Most vulnerable target. This can be decided by a lot of things like affinity, current HP and Def, whether the target has Counter up, etc. CB will almost always aim a target that doesn't have Counter unless they are low HP and a weak affinity, even though the target that gets stunned won't be able to counter attack anyway. Basically assume what ever target is most likely to get one shot with slight variations included for counter buffs, will be the one attacked by it.

That's most of the formula, but there clearly are additional factors.

GoodGuyGlen said:

Most vulnerable target. This can be decided by a lot of things like affinity, current HP and Def, whether the target has Counter up, etc. CB will almost always aim a target that doesn't have Counter unless they are low HP and a weak affinity, even though the target that gets stunned won't be able to counter attack anyway. Basically assume what ever target is most likely to get one shot with slight variations included for counter buffs, will be the one attacked by it.

That's most of the formula, but there clearly are additional factors.

For awhile I was able to consistently get the CB to use his single target on Foli (yay Living Armor passive) over Kael. During this period Foli had both more hit points and more defense than Kael (I actually didn't think defense was counted in, just raw hp totals). I almost want to say that when defensive values (hp/def) are close enough to each other that another deciding factor is chosen, and my best guess is he goes for the one with the highest ATK.

So I have numbers:

Kael:

HP 30,365

DEF 1527

ATK 3234

Foli:

HP 36,487

DEF 1658

ATK 3928

If both are at full health the CB will attack Foli every time. They aren't even really that close in HP, Foli has just over 20% more and he has almost 10% more in defense as well. Both are the same color and generally the clan boss is Void, so that doesn't matter anyways. If the CB AI is set to take down the biggest striker than his choice of Foli makes sense, his attack is far higher (his speed and overall crit profile are also higher).

1. Can i finish him?!  - If CB could possibly kill someone with his highest calculated damage roll, he will attack that one.

   2. Does he have less debuffs than everybody else? (Def up, Counterattack, unkillable, invulnerable)

      3. Is he the weakest Affinity against me ( Red Cb vs 4 Greens, 1 void = void gets the hit)

          4. is the the one in front of the line?

Got a red cb, a red leader, a (blue)foli on place 2, and a (blue) kael on place 3, none of them buffed, none of them one-shot-able?

- Foli will get the hit because he stands in place 2.

Because of this skullcrusher/Foli make good cb leaders, as they are stun immune. Especially vs void affinity cb as the weak affinity doens't interfere.

Athel makes a good stand in lead erbecause her 25% hp bonus, and she can be skilled in defense tree (chance to ignore stun), as she doesn't need anything from the support tree ( given enough ACC), and she doesn't loose any valuable cd-Time while stunned.

Putting Kael as leader makes him prone to the stun - loosing CD-time on his A3 is a bad choice.

if all chars have full hp, he always will attack the char in the middle.

as long my vrask heals every char to full hp the char in the middle (groupleader) will be attackt.

you can see an extended description of if by reading the skills of the clan bos when you fighting it in game