Required Mod.
L_ender's cataclysm is definitely a mod that adds a high difficulty boss but is far easier to beat in a modpack that adds multiple weapons. (unless the creator changes the configuration).
Also in my opinion the boss is more vulnerable than it looks. A player with high attack power can defeat it in a few dozen seconds.
Make the following changes to make this mod boss the end content boss of modpack.
・All bosses
It now absorbs less damage.
・Netherite Monstrosity
Reduces damage taken by 9.
When it reaches a state of rage, it recovers all of its HP and increases its attack and defense capabilities.
・Ender Guardian
Reduces damage taken by 8.
When the helmet is broken, it regains all of its HP and increases its attack power and movement speed.
・The Harbinger
Reduces damage taken by 11.
After taking damage, a creeper-shaped bomb will fly upwards. The Harbinger is not affected by creeper bombs. The Harbinger is not affected by creeper bombs (because they explode before the invincibility expires).
・The leviathan
Reduces damage taken by 12.
Phase 2 restores all HP and increases swim speed.
In phase 2, all recovery is nullified just by being nearby, and the player is constantly debuffed with abyssal burns.
・Ancient Remnant
Reduces damage taken by 6.
After taking damage, it heals HP 6 times. Thus, less damage will only heal Ancient Remnant.
Movement speed is extremely reduced when hit by earthquake attacks.
・Ignis
Reduces damage taken by 8.
Each time it enters phase 2 or 3, it regains HP and its attack power and movement speed increase.
Phase 2 grants blazing brand level I to nearby players, while phase 3 grants level II.
Goety version
https://www.curseforge.com/minecraft/mc-mods/goety-mythical-addon
Illage and Spillage version
https://www.curseforge.com/minecraft/mc-mods/illage-and-legend