Game Mechanics 2 Damage-related Gamemodes

Gamemode 1: Brutal (B)
This first gamemode is a variation to Nagisa's charm penalty suggestion, but instead of being an item you can take off at any time, the debuff is permanent, and only selectable during class creation.
Selecting this gamemode will permanently cause any damage you take to be doubled on that class. Pretty simple.

Gamemode 2: Elemental (E)
The gamemode to pair with Brutal, Elemental would also be selectable at class creation. All damage you deal will be greatly reduced, but, hitting an enemy's weakness will reduce your damage less. There are 3 versions that could be implemented:

Spoiler: Version 1

Attacking an enemy's weakness will deal 100% damage
Neutral damage will deal 50% damage
Attacking an enemy's defense will deal 50% damage

The most player-friendly version. Using a weapon against an enemy's weakness will cause no change from normal gameplay. However, neutral damage and attacking defenses will cause damage to be halved.

General example I'll use for all the versions:
Say you have a 200 water dmg 200 earth dmg 200 neutral dmg weapon.
The mob has -100 water def (weakness), +100 earth def (defense)
100%(200+100) + 50%(200-100) + 50%(200)
300 water dmg + 50 earth dmg + 100 neutral dmg
450 total damage (compared to 600 damage normally)

Spoiler: Version 2

Attacking an enemy's weakness will deal 67% damage
Neutral damage will deal 33% damage
Attacking an enemy's defense will deal 33% damage

The most punishing version. All damage dealt is greatly reduced, making bosses with no weakness (like Qira) much harder than usual.

Again, say you have a 200 water dmg 200 earth dmg 200 neutral dmg weapon.
The mob has -100 water def (weakness), +100 earth def (defense)
67%(200+100) + 33%(200-100) + 33%(200)
200 water dmg + 33 earth dmg + 67 neutral dmg
300 total damage (compared to 600 damage normally)

Spoiler: Version 3

Attacking an enemy's weakness will deal 75% damage
Neutral damage will deal 50% damage
Attacking an enemy's defense will deal 25% damage

Probably the most well balanced version. Favors weapons that target weaknesses while giving neutral damage some room for play.

Lastly, say you have a 200 water dmg 200 earth dmg 200 neutral dmg weapon.
The mob has -100 water def (weakness), +100 earth def (defense)
75%(200+100) + 25%(200-100) + 50%(200)
225 water dmg + 25 earth dmg + 100 neutral dmg
350 total damage (compared to 600 damage normally)

Thus, HICHBE will be: no deaths, no trading/bank/tm/buffs from other players, crafted items only, vulnerable to players in a 10-level radius, take double damage, and deal reduced damage