-
You can manage & track your card collection and decks once you create an account and login.

If I play Brainstorm into 2 Overwhelming Advantages and meet all the requirements, can I do 15 damage to 2 different enemies? Or must they target the same character?

Each Overwhelming Advantage is separate, so they can do damage to different characters.
Source: Wizards of the Coast (2019-11-09)    【Link to Ruling】
Tags: Brainstorm, Brainstorm