Weapon cooldown is still there, but instead of lowering weapon attack damage, it slightly lowers attack reach. Allowing you to hold left click to spam attacks at the cost of reach.

Different weapons and tools have unique uses, switching between them during combat is key. Relying on just one? Not advised.

Each one with different stats like attack reach and armor piercing.

Come with new tricks, and get even tougher once you unlock the Nether or the End.

You'll need better shelter to pass the night, instead of just sleeping in the open, but days last longer, so there’s more time to prepare.

For example, diamond gear protects less and deals less damage:

You’ll need to do the most with the tools you're given. To survive you'll need to experiment with new tactis, and the new weapons and armor added.

No more mindlessly eating to get full hp without a second thought. Natural regen is off.
You can heal by killing mobs as they drop life orbs, it's just enough to keep you fighting a bit longer.
For serious healing, you’ll need items like bandages that give Glass Regeneration effect which breaks on hit. Absorbtion prevents it from breaking. (You can turn wool into string btw).

It gets easier as you progress and unlock better healing gear (see the quests book).

Warrior Rage: A kill streak, the more enemies you kill the more damage you'll deal.

Dodge: self explanatory.

Wall Jump: Cling to walls and leap off for extra mobility.

Falling Attack: Slam the ground with an Area Of Effect attack by crouching and pressing left click while midair (Only works if you’re holding a sword-like weapon).

Dedicated tool slots to keep your hotbar clean.
Offhand has its own keybind that effectively lets you dual-wield cool combos like tridents with riptide and loyalty, or a bow and shield—but you’ll need to configure the Inventorio mod to acomodate it to your liking.

You can move while the inventory is open.

There's tiered bundles, backpacks, toolbelts, everything you need to keep your inventory nice and clean.

You can open a menu to turn enchantments ON and OFF from your items. Which allows for fortune and silktouch combined.

You can do illegal enchantment combination like frost walker and dept strider, multishot and quickcharge (there's no damage immunity for projectiles so shotgun time baby).

You can transfer enchantments from items to books using the grindstone.

Protection has been removed along with some other enchantments, if you're wondering why you can't use some enchantments is because they're disabled, or is now exclusive and can only be applied to one specific item.

All kinds of potions are stackable to 16. And the effect duration is also stackable, meaning that you can have 16 minutes of strength by drinking 2 potions of 8 minutes of strength. The limit is 3 hours (180 minutes)

You can use the brewing cauldron to combine up to 3 potions into one. First light it up with flint and steel. Then Just drop the 3 potions you want to combine into it and drop nether wart to finalize.

Do not use the backpacks feeding upgrade, it doesn't work well with the inventorio mod Utility belt and it could delete items in the belt or hotbar. Use the refill upgrade to refill food from the backpack, alongside the feeder helmet module instead.

If you're wondering why you can't pickup or find some items is probably because they're disabled or hidden.

If you're stuck in a undead army, it could be because ghots are dormant because is daytime without thunder weather. Or you just haven't found the remaining enemy.

When starting i wouldn't recommend to go straight to a big open cave, as mobs can easily overwhelm you in open areas. It would be better to go to a mountain where you can mine lots of iron safely in broad daylight, craft shears to get enough wool to convert it to string to craft bandages. Then go explore a small, corridorlike caves or dungeons where you can easily control fights using blocks to stop mobs from reaching you or flee if necessary.

Just make sure to install the config file, default configs and kubejs files into the .minecraft file.

You can do that by creating a issue in this github page:
https://github.com/xelotex/Absolute-Kombat-2.0