Stop listening to people whinging about how every character is bad. The problem with this game is, every character is too good.

Your main issue in for honor is characters who spam, simple as. Spamming the same combos, spamming dodges and guard breaks, spamming revenge, spamming ranged attacks. Anyone can do it. HOWEVER, certain characters are notorious for the spams, peacekeeper and warlord being the worst by far. Does this mean you should nerf them alone?
No!
I have some simple suggestions which I'm sure would massively balance the game and make it more skill based;

Bigger stamina penalty for guard breaks, guard break counters and dodges.

When low on stamina, movement speed is generally lowered. No dodging away to turtle.

When low on stamina, block damage resistance is lowered.
Again, stops a character turtling.
Give guard breaking a cool down.

No GB-counter-GB-counter over and over till ONE person runs out and loses. No skill in this.

Slow fast attacks down a tiiiiny bit for most characters. Strangely, vanguards seem to be the only sufferers in this. A shugoki light attack can be so quick, its unblockable. Makes zero sense.

Reduce the ability to throw characters. Warlord grabbing someone and pushing them 40 foot off an edge is not honourable, or logical. There should be a choice to counter that at some point. Same goes for raider and lawbringer.

Revenge needs a cool down. It's that simple. Characters with revenge builds that get it in 2 hits are unbelievable, but a cool down will stop them being so stupidly overpowered.

Ranged attacks need a HUGE damage reduction. An orochi should not be able to arrow then dart me and kill me in without any combat. This isn't call of duty, no-one wants ranged attacks.

Stop nerfing and buffing characters or you'll break the game like rainbow six. Just fix big, cross character issues like I've explained and I guarantee the game will be 1000000x better.