Electrodominance has already proven to be amazing in all possible formats in Magic: The Gathering, but Modern is the place where it really shines. Specifically, this card allows you to sneak out suspend cards like Living End, Ancestral Vision, and Restore Balance, and it can do it at instant speed.
If you're not interested in playing combo lists, then you can use it in more secular decks like Jeskai Control or even Burn. Basically, you can do no wrong with this card — that's how powerful it is.
This power comes from its flexibility, which means that you will see it in many different archetypes that use red mana in one way or another.