A level 80 EK (great healths available at level 80) is already capable of soloing Ungreez.
This video shows an 80 EK killing it: https://www.youtube.com/watch?v=p9M4FUfs5UY
Note that to kill it "easily" the guy is using Might Rings all the time, this way he takes a lot less damage and can mana up safely! You can also jump in/out of the teleport to get mana/hp in dangerous situations
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That means that a even lower level EK can kill it if he has a druid healing him.
But what level should the ek be?
Lets take a look at what damage he will be receiving:
- Melee (0-480)
- Great Energy Beam (350+)
- Energy Hit (200-400)
- Great Fireball (180-250+)
Assuming the EK is smart enough to don't stand in front of the boss, then he will never get hit by the Energy Beam, so the maximum damage output will be: 480+400+250 = 1,130 damage
Cheap gear with no level requirements:
- Elven Amulet: 5% Resist on Physical / Fire / energy
- Might Ring: 20% Resist on Physical / Fire / energy
- Mastermind Shield with Intricate Fire Resist: 8% Resist on Fire
- Sun Catcher: 5% Resist on Fire
- Magic Plate Armor with Intricate Fire / Energy: 8% Resist on Fire and Energy
- Zaoan Legs: 2% Physical
- Zaoan Helmet: 5% Physical
Total Resist:
- Physical = 100%*0,95*0,80*0,98*0,95 = 71%
- Fire = 100%*0,95*0,80*0,92*0,95*0,92 = 61%
- Energy = 100%*0,95*0,80*0,92 = 70%
Maximum damage after the resists:
- Melee (0-480) * 71% = 341
- Energy Hit (200-400) * 61% = 280
- Great Fireball (180-250+) * 70% = 153
TOTAL = 341 + 280 + 153 = 774 damage (in worst case)
A level 60 EK has 965 HP
With a druid healing him, he can be pretty safe, since most of the turns the damage taken will be much much lower than 774.