So the game in its current state with the Crusader and the Warden has a major issue. The Crusader essentially has all of the Wardens abilities and simply does them better as well as having more abilities on top of that. Leaving you with no real reason to pick the Warden over the Crusader other than stylistic purposes.

Let's go over all of their unique abilities.

Warden
Duel Light Attack Combo On Side Hits
Unique Parry Option On High Parries
Shoulder Charge After Dash Or Light Hit

Crusader
Chargeable Heavy Attack
All Stances Block At Cost of Stamina
Shield Bash (Same As Shoulder Charge, But Knocks Foes Over)
If An Attack Is Blocked While Charging A Heavy Attack Grants A Unique Parry-Like Option In Which You Immediately Follow Up With a Heavy

Now you might be saying "Well the Warden is supposed to be easier to play so he has less abilities," but no. The fact that he has less actually leaves him with fewer options in a fight making him more difficult to play and overall less viable than the Crusader in every way. Not only that, but it's hard to call a character "Adaptable" if their options are so much more limited than other characters. So I have a couple suggestions to help him fit into his roll of the Adaptable character.

Biggest Change:
I think it would be cool if the knight had 3 different forms he could assume on the fly, changing his strengths, weaknesses, and abilities unique to each form making him more capable and versatile for dealing with certain situations.

Form 1
Default, the character functions as they do now except I think it would be nice if regular parrying stunned the enemy and hit for stamina damage at the same time.

Form 2
The Warden grabs one hand onto the blade and can now preform short range guard piercing thrust attacks. However you lose blocking potential changing your blocks into that similar to that of the Beserker. (without the guard break) Your parry would still stun enemies and deal stamina damage. Unique ability, dashing towards an enemy and preforming a heavy attack will do an unblockable thrust, but leaves you open if you miss. This form would make you more able to compete with the Orochi and Beserker.

Form 3
You grab your sword by the blade with both hands effectively turning it into a club. This form functions more like the Raider. Parrying no longer does stamina damage and no longer stuns. However high heavy attacks will stun an enemy and deal stamina damage. You attack much slower in this stance but do massive damage. You can attack out of side dashes but you will be left open afterwards. Unique ability, throwing an enemy at a wall in this form will cause you to automatically follow up by bashing their helmet with your hilt. (Much like the Raider picks you up and knees you in the face.) This attack deals decent stamina damage and stuns the enemy.

And assuming none of this happens the Warden at least needs a stun and stamina damage on parry. Parrying is all they've really got against the Orochi and Beserker right now. The Orochi is too fast to play offensively against and they're too fast for any of the Wardens current attacks to connect consistently. At the very least the Warden needs a defensive option that deals stamina damage. In the games current state the Orochi can escape anything given that he has stamina. Due to his ability to back dash and heavy attack making him back up farther and get ready to instantly punish whatever attack he dodged.

Edit: This is old and you can disregard all of it. The Warden still needs more options but I realize how overpowered my suggestions were. Still an interesting thought though. I'd like to see a stance heavy character who can change move sets on the fly.