Suggestions For A Super Hard Survival?(plugins And One-commands Only)

Okay, so I want to have a super hard survival on my as yet non existent server. According to what I have planned, it's pretty tough already, but I wanted suggestions. If your suggestion is NOT a plugin or one-command, feel free to say it anyway, as I have a bit of command block skill. The only things not accepted are mods.

What I have so far:

Floating island world gen(almost every biome, including other dimensions)

Thirst

Temperature

Buffed mobs(extreme)

"Decay"

Custom new mobs

Boss fights(to have a goal and a way to win; beating every boss and crafting the drops together ends the game)

Progressively shorter daytime(eventual eternal night)
Dying twice is a game over

Multiplayer

Mobs mutate to nether counterpart with the presence of a witch

Dungeon storming for good loot

Random helpful new items(gliders, jet packs, mob cage)

No health regen?(still deciding;I want this to be possible!!!)


Yeah that's pretty much it. Anyone have any other ideas? >: D

 

Tools with negative effects. (e.g. 40% less speed, reduces damage, etc.).

Or if this is really a super-hard survival, then no tools whatsoever.
It is possible.

 

Some of the items in the dungeon plugin have negative effects. As far as no tools goes, I plan to record this, and I feel like that would make a boring video. Good ideas though! :)

 

This guy has some pretty awesome custom mob commands; Jragon014
And his realistic physics stuff is pretty awesome too! Not sure if it's hardcore though, but it would add a modded feel.
(I built some stuff for him in the past... You can tell can't you :P )

 

*Huge copy-paste list*

Some skeletons shoot 2x as fast
Ghast fireballs home in on players (but don't change direction too fast)
Wither summons minions
All tools lose durability 1.5x faster
Zombies and skeletons are 5x more likely to spawn with armor
Heavy armor slows you down
Arrows fired from dispensers in the jungle biome inflict poison 1 for 5 seconds
Witch throws potions faster
Zombie Pigmen are 25% faster
The cliche players killed by zombies turn into zombies
Lava deals 1/2 heart more damage
Skeletons deals an additional half heart of damage that pierces through armor
Take damage very slowly if within ~2 blocks of a fire or lava block
Passive mobs become neutral
Weapons with lower durability deal slightly less damage
Squids shoot ink that can blind you
When you respawn/spawn, you have blindness for 5 seconds, and during that time, you can't attack, be attacked or interact with blocks.
Ender Crystals shoot harming lasers at you when nearby
Creepers are invincible and have speed IV
Skeletons holding any type of hoe will deal 7 hearts of damage per hit
A creeper will become charged if it stands too close to a powered redstone signal
Silverfish spawn in dark areas below y:48
The Wither occasionally becomes supercharged and shoots wither skulls extremely fast for ~5 seconds
Endermen in the sky biome (end) automatically become hostile if you go within 16 blocks of them
When ender crystals explode, they shoot out fragments that explode too when they collide with a block
Blaze cooldowns are reduced by a bit
Enderdragon and Wither have more health
If a creeper is in pursuit but you are out of reach for a while, it will simply give up and explode
Fire spreads easier
You deal 1 less damage if you are in a light level of 6 or less

I'm not sure even half of this would fit your requirements, but whatever.

 

Holy shit
I'm imagining the lag right now