I don't know if you'll be able to prevent large scale teaming of already OP players, but let's think about it logically just in case my train of thought inspires a solution...
The reason teams are nessasarry is because to take down a lone p2 diamond or better player, it takes no less than 4 people using 6.25 damage per hit to take them down effectively, 2 of them rushing in together and flanking, and the other 2 sniping/regening health.
But our "loner" can avoid this by simply teaming up with an equally OP player. It would now take tactically luring them apart and 8 people working coherently in 2 teams of 4 to kill them. And eventually, they reach OP team sizes of 6-7 and become effectively invincible, as no more than 7 people can engage on player in combat at a time without specialty suited terrian.
Let's just say 30 people are on kit pvp at all times. Let's also say 15% of all players donate to a degree. This means they can make money faster by unlocking more and more players they can effectively kill, and essentially means they will complete p4 diamond weeks before normal players. Let's say 5% are vast or higher, and in those kits can take owin man teams and win. Think of it like a <<high breed>> of players. There's not many of them, and fighting each other is faaar more tedious and resource intensive than an extra set of broken /vast is worth to them. There's no point in fighting each other, even if they both have teams and one is clearly stronger than the other. Some of their team is highly likely to die fighting another <<high breed>> team. As such they divy the map into areas, jungle, field, palace, sand town, and chapel valley, the field being the best noon hunting grounds for the easy cash and non renewable resources , I.e. ender pearls and g apples neccassary to fight other <<high breed>> teams, and the teams at field, chapel valley, and palace thrive off of easy kills on non OP players. And as the noob supply is ample and ready for the slaughter, there's no point in risking a fight with equally equipped foes unless they come to your position, which gives you a better chance of not being repelled.
A solutional.
In an mmorps I play, they had the same problem. No one chose high risk fights over garunteed easy, farmable loot. Then they added a system called <<Bounty Hunter>>, which determined the value and quality of your gear, and then gave you a name of a player with similar stats, and an arrow showing you their general direction. Killing THAT EXACT PLAYER before killing anyone else yielded rare, high quality weapons, armor, potions, and even cash rewards...
A similar system would encourage betrayals amongst the large teams, Because their teammates name popped up, and they valued the chance at, I don't know, a sword that holding it gives strength lvl .3, which is ~ 6.8% damage bonus, and that fear that your friends are likely to be assigned to kill you for loots far better than even a week of noob farming would make it incredibly unlikely to see teams larger than 3 people, because they would have to know each other IRL to have resist the urge to kill for the chance of a crazy good weapon.
Head possible potion effects: negative value on the hunger rebuff, resistance?
Torso possible potion effects: regen, fire resist
Legging possible potion effects: jump boost, speed, fire resist
Boot possible potion effects: speed, jump boost, damage seeping.
Damage seeping is Something I'm not sure about, but my understanding is its like thorns except different, it deals area of effect damage based upon the damage taken. Typically it only works when falling, poisoned or on fire though, unlike thorns. Hence its useful to have even with full thorns
Also, because before keeping exp on death, there was an issue with forced teleports to people whom had just leveled up, and its likely the same problem would occur with rare drops, to fix this preemptively, the item should be dropped into their player vault, and if it is full, they could type a command to claim it later. Also I'd love a broadcast to occur when someone gets a rare item bounty... Also the potion drops I had in mind were resistance potions, 20 second str 5 pots that also give slowness 2 and hunger 5 for 15 seconds
, you can deal full, unlockable damage, to anything within sword range :-D
