Wikia

Original	First Errata
Activate only during damage calculation when the ATK of your battling monster is lower than the ATK of your opponent's, and pay Life Points equal to the difference in ATK. Your monster gains ATK equal to that difference +300, during damage calculation only.	During damage calculation, if your monster battles an opponent's monster with a higher ATK: Pay Life Points equal to the difference in ATK; your monster gains ATK equal to that difference +300, during damage calculation only.
Crossroads of Chaos CSOC-EN067 Added by Rodtheanimegod4ever	Battle Pack: Epic Dawn BP01-EN100 Added by Look234

Card Errata:Prideful Roar