I have three character slots and I generally like one of them to be occupied by a Knight.
After my last Knight death I decided to make a Warrior though.
Got him to 3/8 (DEF, DEX, SPD, with VIT and ATT close) and was rushing an Abyss last night when out of nowhere his HP plummeted insanely fast and I RIP'd...
I've decided that Knight is the only melee class actually worth a shit.
I really like how the Warrior does lots of damage, but imo the Knight is just a lot more viable as I can just sit back and hardly pay attention while rocking the Godlands.
And I don't think I've ever RIP'd a Knight rushing a dungeon.
I'm tempted to try a Paladin again just because I want something that can deal more damage than a Knight, but I don't think I'll be able to keep anything alive as long.

my warrior has no issue.
I use a.s.s/pixie
candy armor
ggen
pyra

so I have only 6 less def than a knight with tops.
my pet is like 90/84/7x though with electric so I can perma buff any class.
but I fly throught abyss' , and would never look back at knight. and I played knight long enough to hit 7500 base fame from just dungeons. no fame farming.
now my warrior has around 5.1k base fame and living. and I love it way more.

I suicide my knight btw, they are a great class too don't get me wrong. but I LOVE the speed