I will start with passives first because I cannot select them right now. First is greatsword passives:
Vital force is a must have. Hit chance, skill damage, stun chance. All are good. Must have on all gs builds
Robust constitution is 2k health. The passive above this one gives you bonus hit chance, skill damage and stun chance with each 100 health you have. Another must have.
Cold warrior is the last must have from the GS. 100 hit chance plus bonus heavy attack chance on stunned and shocked targets. Must have for greatsword.
Raging Frenzy is great in fights with lots of enemies close by. Honestly get the most out of this with trash mobs in dungeons, mob farming in open world dungeons and events. And large scale pvp events. If you know the fight doesn't have many enemies that are bunched up don't bring this you won't get anything from it.
Victor's morale is useful in pve if you have mana problems. I would not recommend in pvp.
Indomitable armor is a defensive buff with 25% chance to proc when you get hit, granting a defensive boost for 2s that can stack 3 times. Useful in pvp and solo farming. I don't use it when i am in a party as we are dps not tanks.
Barbarians dash is a great mobility passive giving a huge move speed boost after using mobility skills. This includes your dagger skills, anything labeled as movement or mobility which includes the dagger parry.
Rotation one is big damage in pvp. You can save stealth and use it as an escape at the end if you'd like. You also have an extra stun and prone ability after this combo, or if you miss another skill during the combo.
Once people know how you combo they may try to predict your stuns with a parry. If you use ankle strike or ascending slash while they parry you will get a knockdown. IF YOU GET A KNOCKDOWN IMMEDIATELY USE YOUR GUILLOTINE BLADE FOR BIGGEST DAMAGE. it has a huge 900% damage scaling on shocked and proned targets so take advantage of that.
Use the best quality healing pots you have. I have about 500 saved from just buying them daily which is easy enough to afford if you play for a little and have a guild. Mana pots can also be useful too if you struggle with mana consumption. I use my attack boost pots in pve. I use the defense pots and purification stone in pvp. If i know I'm going to be diving i will pop a defensive pot to reduce damage i may take. The damage/defence pot and purification stone do share a cooldown so beware! Choose carefully.
All of these foods can be useful in any quality level as it appears to only effect the buff duration. Adapt your food to fit situation and your build. If you need hit chance use that food to help. If you want to pump out more damage use a food that complements whatever your build does. I like to use health food with a damage buff food in pve, in pvp I use an evasion food buff and
I use shade revenant because it is a big dps boost. I think some people forget about these but they can be very useful. Brutal warrior can be useful for select situations in pvp where you have some sort of healer to help you not melt but taking damage is not what we like to do with our evasion build. I would recommend shade revenant since you can use it on cooldown in pve. In pvp I would use it right after jumping on someone from stealth. Singled out enemies will take all 5 of the thrown daggers.
