Adamant heart: being a leader of an adventurer's party

You are the leader of Adamant Heart, an adventurer party made of invaluable members: Cassandra, the mighty beastwoman who fights vigorously with a heavy sword and a heavy shield. Evelyn, the elf cleric, sister of Elias, that keeps your party in good health with her sacred spells. Elias, the great elven archer, brother of Evelyn, that can strike a target far away with his bow. And then there's you, their party leader... you are not strong, you can't fight, you can't cast spells... Guide them with your cunning and incredible strategies and your ability with magic artifacts, being one of the few that can use more than one at the same time.