Sorry about that. I found this bug to be extremely odd.
It was occurring based on the card language setting at game startup.
If you have it set to Japanese, you should get the same bug. If you change the language setting later, the message will still be wrong.
Message text in Japanese may be untranslated or incorrect.
Specifically, the message for the Heatsoul is “攻撃力アップ”(Increase ATK).