Mardu Aggro based on Osyp Lebedowicz's GP Miami deck. (Standard)

This is a take on Osyp Lebedowicz's Mardu deck that he finished ninth with at GP Miami. He played Chained to the Rocks, but I don't think that's where you want to be right now. Taking the core elements from the R/W Aggro deck and adding Sorin, Solemn Visitor and Cracking Doom feels really good. Crackling Doom is definitely one of the best cards against Heroic, and with the rise of hexproof Dragons in the format with Silumgar, the Drifting Death and Dragonlord Ojutai, Crackling Doom is ready to make a comeback as one of the best removal spells in Standard.

The number of Wild Slashes has been lowered in response to the more control-heavy metagame. While Foul-tongue Invocation makes a burn plan less appealing overall, I really like how Crackling Doom plays against big untargetable Dragons. Sorin, Solemn Visitor is a big player too, as the +1 further pressures Esper Dragons with your current creatures without overcommitting, and the -2 Vampire give you an opportunity to grind them out with a touch of card advantage. The ultimate of Sorin, Solemn Visitor is unbeatable for Esper Dragons now as well.

What makes a light splash the way to go?

Many factors plague decks trying to reliably hit all of their colors as early as the third turn. Manabases end up painful, and their spells can't be cast on curve. Standard is chock full of powerful spells, and light splashes seem as easy as they've ever been given that there are Temple options of all combinations. The fine balance between power level and consistency regarding castability of your spells currently seems to be with a gentle touch of a neighboring color for a powerful rare or mythic.