Look at GT’s monster database to learn what’s killing you. Father Kymon is EXTREMELY dangerous. I would know because I pilot predominantly glass cannons.
The trick to kymon is to bait out his pounce. You do this by…
- Not moving for ~1s
- Immediately moving or dashing away from the spot you’re at.
- (For bonus swag points, dash towards kymon as he’s leaping. You’ll damage him, but he won’t damage you)
Once you’ve baited out his pounce (it has a 7s CD), he’s immobile for 1s. This is when you get right up in his face to bait out his lava shotgun.
The moment you see him trying to chest bump you, dash tf away.
Now you have about 5s to unload the pain on kymon. He’s pretty harmless without those 2 skills.
Why are these 2 skills dangerous?
^Stats listed is for kymon in ultimate
So…900 cunning is approximately an additional 400% physical damage, and 800 spirit is an additional 350% magic damage.
In other words, each projectile from kymon’s chestplosion does…
524 * 5 = 2620 physical damage
529 * 4.5 = 2500 fire damage
Couple that with the fact that his pounce shreds DA, and his chestplosion melts armor… 
Here’s a gif with demonstrating how I outplay kymon on glass cannons in unbuffed/unbannered crucible.
Obviously each mastery offers different forms of defences against enemies. The trick is to always find the best way to maximize the tools provided by the class combination you’ve picked.
While the mechanics of each defensive stat works the exact same way on each and every spec, the amount of utility a certain class combination might get out of e.g. armor varies.
So…build to your strengths, while finding ways to shore up your weaknesses.
I hope this makes sense.
Or you could take the time to learn the combat mechanics of enemies and outmanoeuvre them