Using Janbjorn on Nova, using a basic attack should allow me to choose which ability to use first (ready the Helmet with Nova's response ability or using Janbjorn) since both triggers at the same time, after using a basic power and after and the hero attacks. That way the resource from the Novas Helmet can be used for the Janbjorn trigger.
Also, playing The Locust Ally allowed me to return any Aggression Card, it should be only Aggression Events. Here is the deck tested.
*In the next Black Panther pack there are a lot of cards that triggers after a basic power is used, it would be wise to check the timing sequence so no issues like this arise in the future.