What do you want?
AOE:
Archer 2 Sapper 2 Wugushi 2 Cannoneer
Archer 1 Ranger 1 Sapper 2 Wugushi 3
Archer 1 Ranger 1 Sapper 2 Wugushi 2 Cannoneer
Archer 2 Ranger 1 Wugushi 2 Rogue Falconeer (Multi shot + circling, feint + barrage, throw gu pot + capture)
Archer 2 Ranger 1 Wugushi 2 Falconeer Cannoneer (Circling will make cannonblast crits clear waves and waves of monsters).
Single target:
Archer 1 QS 3 Wugushi 3
Archer 2 QS 3 Wugushi 2 (More AA crit centered)
PVP:
Dont roll wugushi.
Stats: If going for wugushi c3, full str.
If not, you should select a balance according to what items you are gonna use. The monster with the strongest crit resist in the game has 195 crit resist. To have 99% crit rate on a 0 crit rests mob, you need 666 crit rate. To crit on the mentioned mob, you need 861 crit rate.
This simply isnt achievable alone. What you should include is support from other skills (swift step, monstrance, zalciai, quicken), so you will peform greatly with them. Putting one support out of the paper simply makes too much more dex necessary, and you need STR to boost wugushis poisons.
Formula for how much dex you want to have is:
1,3DEX + 10 + 1,25(DEX + crit rate from gear and collections + crit rate from level bonus (at 280, it is 56)) + 0,25 (DEX + crit rate from gear and collections + crit rate from level bonus (at 280, it is 56)) = 861
This way we get to
1,3 (DEX + DEX from gear) + 10 + 1,5(DEX + DEX from gear + crit rate from gear, gems and collection + 56) = 861
DEX is dex you have after investing points. DEX FROM GEAR is dex points from gear, like max pentaminion for an example. Crit rate from gear is any crit you get that is not from DEX.
generally, you will have every number but DEX. Define your gear, and you will find the DEX you will want to have.
According to the testings of a discord mate, crit resist can go below zero, but as most spreadsheets simply bug with this, lets consider a 100 con rest spr support cleric uses zalciai. The 195 crit resist will be lowered down to 0. Now you need 666 crit rate. Then we get to:
1,3 (DEX + DEX from gear) + 10 + 1,5(DEX + DEX from gear + crit rate from gear, gems and collection + 56) = 666
1,3 DEX + 1,3 DEX from gear + 10 + 1,5 DEX + 1,5 DEX from gear + 1,5 crit rate from gear, gems and collection + 84 = 666
Now we can finally get to: 2,8 DEX + 2,8 DEX from gear + 1,5 Crit rate from gear, gems and collection = 582
2,8 (DEX + DEX from gear) + 1,5 crit rate from gear, gems and collection = 582
If you observe, most of support skills from this game benefits physical damage. Currently, magic damage alone does better than physical damage, but thing is, support is there to make physical damage stay on par with magic damage in party scenarios. Physical damage dealers are just more party dependant.
Example:
Considering Max Pentaminion, Mana Mana, Level 5 green gems, 8 crit rate from collections, 56 crit rate from lvl 280 bonus, double sissels bracelet, best rools on headgear for crit rate (14 for each).
Max pentaminion: 14 DEX from gear
Mana Mana: 35 crit rate from gear
Level 5 Green Gems: 22 crit rate from gear times 2 on main hand. 29 crit rate from gear in off hand.
Double sissels bracelet: 74 cri rate
3 Head gear OH lord luck: 42 crit from gear
Now we have:
2,8 (DEX + 14) + 1,5 (35 + 44 + 29 + 74 + 42) = 582
2,8 DEX + 39,2 + 336 = 582
DEX = 206,8/2,8
DEX = 73
Now you will invest into dex until it is 73 without any gear.
Of course, this is really dependant on what you want to consider. Monstrance formula is 1,3DEX +10. Quicken and Swift step buffs are the same, 0,25 times all your crit rate. Zalciai is simply the most powerfull debuff in regards to crit rate. If you dont want to consider some of these, the formula would change. It isnt anything complicated, but if you hate math…
Note: 138 DEX alone is enough to make you get high crit if you want to depend solely on lvl 5 green gems and not anything else.