Adventurer rank: Bronze -> Iron -> Silver -> Gold -> Platinum -> Diamond -> Mythril -> Orichalcum -> Adamantite -> Luminite
Mercenaries: F -> E-> D -> C -> B -> A -> S -> SS
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Monster rank
Common: People who can atleast use weapon can handle monsters with this rank.
Uncommon: Monsters that can only be beaten with people that are trained with using weapon, like militia, adventurer with Iron rank or mercenaries with E rank can defeat monster with this rank too.
Normal: Needs a Silver ranked adventurer or D ranked mercenaries.
Rare: Needs veteran soldiers, Gold ranked adventurers, or B ranked mercenaries to handle.
Legendary: Only a Platinum ranked adventurer or A ranked mercenaries can defeat monster with this rank.
Mythical: Only adventurer at Mythril rank or Mercenaries at S rank can defeat monsters with this rank.
Harbringer: Only the combined forces of Adamantite and Luminite rank adventurers with the help of SS rank mercenaries can defeat monsters with the Harbringer rank. A group of Luminite adventurer can also defeat monster with this rank, but they will not come out unscathed, the possibilities of being wiped out are high.
Demi-God: Nigh-impossible to defeat.
God: No one has ever seen a monster with a Demi-God level, same with the monster with God rank. That aside, monster with God rank are impossible to defeat, at least for now.
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Weapon rank
Common
Uncommon
Normal
Rare
Ultra Rare
Legendary
Mythical
Demi
Zenith