Archangel Avacyn seems like an obvious addition, since it does everything, and Oath of Nissa is going to complement Gideon Ally of Zendikar, the most powerful card, by finding it and helping cast it
Melee scales with the number of opponents youve attacked in a given turn, and so on
This red enchantment is just good as a helpful piece of burn-based interaction in an energy deck in EDH, and it also burns out the table once you get one of the many infinite energy combos the top-tier of energy cards can shuffle together to generate
The ability to exile specific cards is always useful, and this engine becomes more dangerous the more you use it
Lets say that you have [c]Blightsteel Colossus[/c] and your opponent attacks you with their [c]Worldspine Wurm[/c]
However, the 6,000 Power makes it more of a challenge for opponents to get their attacks through and will require fewer Counter resources from you to shut down attacks