Alphonse Elric

Anime illustration: a boy in a red cloak with a metal arm stands in a glowing golden alchemy circle beside a tall, hulking suit of armour, both looking up at a huge luminous set of balance scales hanging overhead. — Original artwork

Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. That is alchemy's first law of Equivalent Exchange.

Alphonse Elric