I just don't see a situation where this set really is worth much. You would think a DK with 40% to heavy attack could make the most of this but in all honesty there is just such a small window where you would be able to get fully charged heavy attacks off on someone once they are 25% health that the 5 set bonus is kinda worthless. It would be better to have a 5 set that gives light and heavy attacks a small bleed or something then increases at 25% health.
As it stands the only way to really use this is to spam light attacks for the few seconds where your target is low. The fact of the matter is that the way executes work in this game every single person with an execute will be doing massively more damage by the time the target is at 25% health so the % of time they stay below 25% health is so small even on bosses that it just doesn't make up for the other 90% of time where they are above 25% health. Basically you will spend 90% of the time fighting something above 25% health and then when they hit that threshold they either get a big heal or die in a matter of seconds. If its a boss it might last another minute or so but that is such a short period of the fight that you wont be getting a lot of big heavy attacks in, and light attacks are not that significant when compared to executes plus any other set benefits you for the whole fight.
Here is a link to the set:
http://elderscrollsonline.wiki.fextralife.com/Kvatch+Gladiator+Set
Legendary Archer of Valenwood
Bosmer Dragon Knight Archer. XBox One. (Flawless Conqueror Bow/Bow)
Bosmer Nightblade Archer. Xbox One. (Flawless Conqueror Bow/Bow)
Bosmer Sorcerer Archer. Xbox One. (Flawless Conqueror Bow/Bow)
Bosmer Warden Archer. Xbox One. (Flawless Conqueror Bow/Bow)
Templar's are evil..