This Is How They Work:
Duplicate Champions will be turned into Gold, higher-tier crystal shards, and class ISO-8 that are specific to the class of that Champion. Duplicate Champions can also potentially unlock or upgrade the signature abilities of that Champion. While the amount and level of the rewards will depend on the tier of the Champion, duplicate 1-Star Champions will NOT unlock or upgrade a signature ability, nor grant you crystal shards. These features are only available for 2-Stars Champions and up.
This system will allow you to gather crystal shards for better Champions!
Once a signature ability has been unlocked, the stars of that Champion will change color from the original gold to platinum.
Maximum Signature Ability:
Duplicate Champion rewards are different for Champions whose signature ability has reached its maximum level. Additional duplicates, after the maximum level has been reached for 2-Star, 3-Star, 4-Star, and 5-Star Champions, will reward a max signature ability crystal.
Note: Duplicate 6-Star Champions and Champions that you can obtain in arenas will NOT grant max signature ability crystals, nor will you earn max signature ability crystals from duplicates obtained via Alliance Crystals or Arena Crystals.
Max signature ability crystal rewards depend on the of the duplicated Champion:
Duplicate 2-Star Champion
Duplicating a 2-Star Champion with a signature ability at its maximum level will reward you with a 2-Star Max Signature Ability Crystal. This crystal has a chance to drop 3-Star Hero Crystal Shards with a rare chance at providing a 3-Star Iron Fist (Immortal).
Duplicate 3-Star Champion
Duplicating a 3-Star Champion with a signature ability at its maximum level will reward you with a 3-Star Max Signature Ability Crystal. These crystals can drop 4-Star Hero Crystal Shards, 3-star signature stones, or 3-star awakening gems with a rare chance at earning a 4-Star Iron Fist (Immortal).
Duplicate 4-Star Champion
Duplicating a 4-Star Champion with a signature ability at its maximum level will reward you with a 4-Star Max Signature Ability Crystal. These crystals can drop 5-Star Hero Crystal Shards, 4-star awakening gems, or 4-star signature stones with a rare chance at earning a 5-Star Iron Fist (Immortal).
Duplicate 5-Star Champion
Duplicating a 5-Star Champion with a signature ability at its maximum level will reward you with a 5-Star Max Signature Ability Crystal. These crystals can drop 5-star awakening gems, 5-star signature stones, or 6-Star Hero Crystal Shards, with a rare chance to obtain 6-Star Iron Fist (Immortal).
The rules for maximum level signature abilities do NOT apply to Punisher, Unstoppable Colossus, and Champions obtained through arenas. These Champions will NOT earn signature ability crystals once they reach the signature ability maximum level.