the gladiator is currently a hero with good combos and good tools for offense, but even so he still remains a little chosen character, perhaps for the stamina and the life he has
my suggestion is
-increase the gladiator's life by adding 20 or 40 more
-Add more time in active guard time, maybe 50 ms or 100 more
-light attack increased from 15 to 16 and finishers from 16 to 18
-attack with shield remove more stamina from opponent
- leave the skewer in the foot more slowly, adding more 20 or 70 ms of the current one
-zone attack more slower, adding 30 or 80 ms of current
-heavy Finisher attacks have increased damage from 30 to 35
is a mini rework changing things very simple that can make the character more playable
leaves your suggestion of what else to change
stay with the idea ubisoft.