Hard to leave this guy out of builds in his colours and one of your best cards when you have other good artifacts that pair with him
Its effects make it particularly good for modified and enchantment decks, but you can run a different archetype and still use Roaring Earth
When Chandra, Pyromaster first appeared, I explained that her middle impulsive-drawing ability came out of discussions about red's slice of the color pie on my blog (called Blogatogcheck it out) and it was something we were trying out in red
Its a cheap spell to sling, it works with reds increasing pool of discard synergies, and it interacts favorably with graveyard strategies
Eventually, the target will change form to become a Shiny Pokmon
Combining the different themes is easy because it all uses the same mechanic and gives you great amounts of freedom on creating a style of deck you like