Suggestion: (H)NM Intimidation - All creatures not of the same species within the area of an NM and of significantly lower level of said NM, will not aggro.
Suggestion: Revenge Striking - We now have /blockaid, and so, this becomes possible. You may engage attack on any mob that has hate for you. Doing so will cause the mob to go into Called For Help mode until it has erased hate from either you or the other player involved, at which point it becomes claimed by whoever is left on hate list. This will, in turn, cause a lot of arguments about players stealing each other's XP mobs, but since it goes into Called For Help mode, why would one do this?
Suggestion: Zone/Death Hate Decay - When a mob has lost its target through the act of target zoning or dying, they retain their hate level for target for awhile, and remain claimed by that target/that target's party even though they are wandering back. This hate will have to diminish much faster, based on how much the creature moves, rather than how long ago their prey zoned. Creature loses all hate it has accumulated for everyone at that rate, therefore since the person with the highest hate is likely to be the one that zoned it, it will essentially return to party claimed ONLY if they built up so much hate on it that it returns to where they are before it loses all of it. Creature also does not aggro during this time.
Suggestion: Lose Track - Monsters that aggro and track by certain means should permanently lose track of someone who has managed to escape enough to get sufficiently covered, or run through water, or such. This would somewhat prevent accidental MPK.
Suggestion: HNM Roaming Triggers - As you have done for the Chocoboleech in the Dangruf Wadi. (I can't help but feel this was a test for such code, and it is a great one). Have the HNMs spawned by CRAFTED item with a moderate failure rate or that requires a series of synths to get all the items involved (also something I've noticed being done) and have the spawn point move around within a small area rather than the HNM itself randomly appearing. When Item is traded to ???, NM spawns claimed to party/alliance that did so. As with other such creatures, NQ spawns normal HNM, HQ spawns normal HNM but with higher droprate, HQ2 spawns King HNM or something similar, HQ3 spawns King HNM with guaranteed drop. NM despawns when all members of party/alliance fighting are defeated and AFTER it has lost all interest due to Zone/Death Hate Decay. (And just for the sake of looking cool, make NM despawn some sort of event). Of course, the ??? could appear only every few hours after the death/despawn of the last creature spawned from it, say 4 hours or so.
Suggestion: Sneaking into Zone - Players should be undetectable for about 15 seconds after zoning into just about anywhere EXCEPT by mob that still has Retained Hate. There is no reason currently why anyone should be instantly attacked when zoning, nor any area I know of where instant assault upon entering the area is part of the game mechanics.
The suggestions hopefully all retain the current harsh competitive atmosphere, but causes MPK to be far less outright helpful since the mob will just despawn after awhile, and since whoever managed to build the most hate on it will retain claim even if they must run/end up dead. Due to /blockaid's availability, players can now choose if they wish to be helped and risk losing the creature, or go it alone and risk death.