My points are:
-He is the best armored champion (as he looks like) among the non-frontliners, and he has the highest burst potential among the flankers. So I suggest to increase his health and reduce his damage.
-His Defiant Fist was OP, but after the Defiance nerf it became a little bit under powered. My change proposal isn't a hugh buff, just compensate the suggested dmg nerf of the Defiance.
1;
Reduce the damage of the Revolver from 520 to 500.
Reduce the damage of the Defiance from 520 to 400.
Increase his health from 2000 to 2200.
2;
With the old Defiance his Defiant Fist increased the damage of the next Defiance by 105dmg/shot up to 700dmg bonus. It was OP.
Now it increases the damage of the next Defiance by 78dmg/shot up to 520dmg bonus. It is a little bit UP.
I suggested to nerf the dmg of Defiance and suggest to increase the dmg bonus of Defiant Fist from 15% to 30% (120dmg/shot). and increase the limit from 100% to 150% (600dmg).
I seems to be closer to the old, OP version, but don't forget to calculate with the much lower basic damage of the Defiance!
For the comparison, the old max dmg with Defiance was 1400 and you needed 7 shots to reach it.
The current max damage is 1040 and we still need 7 shots to reach it.
The new max dmg would be 1000 but we need just 5 shots to reach it. The lower dmg is compensated by the higher max HP.