Knight is bad, but if you really need to know a good build...
setk
This build was updated for
January 2, 2017
Seriously though, even with a Class Gem, knight has bad damage, and is a mediocre tank, I wouldn't recommend playing knight, but here's the guide.
LevelingFarmingTankDamage
Stat Priority
Hat 
Weapon 
Face 
Ring Notes: Knight's abilities are very reliant on Energy Regen, so you need that on ring and melee.
Ally and Flasks
Samantha also works, and can be better if you are the main tank in an ST.
2nd Emblem depends on many things. If you are farming/DMG in ST, and have LOW CH (CH is crit hit chance), choose Surestrike, if you are farming and have HIGH CH, pick beamer (or an equivalent), if you are the main tank in an ST, you want Vampiric, and if you're still not doing well tanking, swap martial for Unyielding.
Empowered Gems
Spirit Squire Class Gem
Charge no longer propels you forward.
Instead, a Spirit Squire charges forward through multiple enemies, dealing damage and stunning them.
Pyrodisc
Killing an enemy has a chance to generate a flaming disc that damages nearby enemies.
This gem has a cooldown.
Explosive Epilogue
Killing enemies causes them to explode.
\n\nThis gem has a cooldown.
Comments
Like
ROROisultimate
Cats_Sky
TankyTanky