Here are some ideas i had to tackle the current grudge mark situation without overhauling the whole system. Some of them have more implications than are apparent at first glance, so please comment on what you think. Ah and of course: i do not claim any copyright on these ideas in case some of them are getting implemented 
1. Illusionist - Mark periodically summons 3 mirror images of itself
Idea 1.1 There can only be 3 mirror images at a time
Idea 1.2 Damaging an illusion also damages the original
Idea 1.3 The original uses his own health pool as resource to create copies of himself
Idea 1.4 Illusions do not apply any grudge effects the original has
2. Relentless - Mark cannot be staggered
Idea 2.1 Mark can only be staggered by explosives
Explanation: Legding by skill usage is still prevented, but freeing teammates from chaos spawn is possible. Also increases the usefulness of endless bomb potions and explosive barrels.
Idea 2.2 by @Mike137 Monster receives one stack of stagger if an attack is parried
3. Rampart - Mark is immune to ranged damage
Idea 3.1 Mark is immune to ranged damage, except critical hits and headshots
Idea 3.2 Mark is immune to the first n ranged attacks
Idea 3.2 Every melee attack makes the target vulnerable to a ranged attack [stacks up n times]
Idea 3.3 by @Mike137 Damage dealt by skills get a negative damage multiplier [or monsters receive no damage from skills]. Damage dealt by regular attacks get a positive damage multiplier.
4. Crippling - Mark severely cripples player’s it deals damage to
Idea 4.1 Crippling debuff is removed when player’s movement speed is positively modified
Idea 4.2 Crippling debuff is removed when receiving team damage
Explanation: The original idea was to implement a small ‘stagger’ or ‘push’ on team damage, so others can free me from the debuff. Even if there is no team damage on recruit and veteran, the system for team damage is already implemented and might be usable without dealing actual damage.
5. Shield-Shatter - Mark breaks blocks and briefly prevents stamina regeneration
Idea 5.1 Shield does not break when the monster’s attack is parried
Idea 5.2 Attacks can be blocked with an actual shield
Idea 5.3 There is a new block potion which grants 100% block power for n seconds
6. Regenerating - Mark regenerates health over time
Idea 6.1 Monster can not regenerate if poisoned or on fire
7. General Ideas - Other ideas unrelated to specific grudge marks
Idea 7.1 New miracle on fortune shrines: Death potion - When drunk, the player receives a permanent debuff until end of the level or downstate. If player goes into downstate, he dies instantly in an explosion, that turns grudged monsters into normal monsters [or strip them of n grudge marks]
Idea 7.2 New miracle on fortune shrines: Calming bomb - When thrown onto a grudged monster, it loses 1 random grudge mark.
Idea 7.3 Grudge spikes on the backs of monsters can be damaged. Destroy them to get rid of grudge marks
