Inspired by Lightning Blast.

I like this design. It feels like a white card better in Boros rather than a mono red card that doubles as a mono white card.

Thanks.

.... huh. Source cardset is now hidden. Annoying./

The original inspiration was basically the same card; except red but you could instead cast as white to add a restriction. This way round, paying more to remove the restriction, feels more natural to me.

The easiest way to implement it in the rules would probably be

> "This spell costs less to cast if it targets an attacking or blocking creature."