Guest joining the suspicious Hero Party

Astellia is a traditional medieval fantasy continent where natural mana circulates through the land, living organisms, and ley lines. The Terra Empire in the center, the Lionheart Kingdom in the west, the Luminous Holy Order in the south, and the Ether Merchant Union in the east form the civilized sphere, while the northern permafrost Calydon is ruled by the Demon King and the demon legion. The four powers compete for leadership, doctrine, and trade, but respond jointly to northern invasions and continent-level disasters. Humans, elves, beastmen, and dwarves coexist in cities and independent communities, and the Adventurers' Guild manages requests, promotions, subjugations, and missing person records beyond national borders.

Combat power is classified into F, D, C, B, A, S, X, and EX. F-E are civilians and soldiers, D-C are skilled combatants, B-A are core unit members and city guardians, S are strategic assets that determine the fate of a nation, X are legendary powers like the Demon King and mythic ancient dragons, and EX is the realm of transcendents unreachable by mortals. Swordsmen condense internal mana into aura and sword energy, mages calculate phenomena with formulas, runes, and spells, and clerics deploy healing, purification, and barriers through faith and spiritual resonance. All powers consume physical strength, mana, concentration, and spirituality; excessive use leads to blood vessel damage, loss of consciousness, and mana backflow.

The demonic energy of the Demon Realm erodes the mind and blood vessels, corrodes matter and barriers, and is weak against holy power. Monsters are not categorized by race but by grade according to growth, mutation, and environment. Demons and undead appear in the north, harpies, ogres, and drakes in the west, wyverns and chimeras in the center, and hydras and krakens in the east. Corrupted spirits and void monsters may appear in ancient ruins and dimensional rifts.

EX-rank transcendents exist in the Celestial Realm, Demon Realm, Ancient Dragon Realm, and Dimensional Rift, but they cannot descend to Astellia in their true forms due to the Dimensional Non-Aggression Treaty. They only project revelations, blessings, contracts, holy relics, kin, and limited clones. The seven strongest swordsmen of the era are called the 'Seven Swords of the Continent,' and the top powers of each nation are called the Empire's Five Poles, the Kingdom's Three Stars, the Radiant Twin Seats, etc. A Hero is a mission-type hero who grows to face the disasters of the era, and this Calydon Expedition is composed of the top-tier powers selected by the four forces and the Guild.

(Monster Encyclopedia and Hierarchy according to Rank)