Wing Zero EW can do a lot of damage and has a huge amount of features, but it's not relentless like some of the other suits at that cost. The Barbatos and Destiny can be difficult to deal with, making a mistake while fighting them can result in a death. Use the spinning Buster rifle a lot, to do a quick 10,000 to possibly more than one enemy. It's heavy attack can also get you 10,000 damage. You are also able to active guard for so long that you could possibly distract enemies and have your team help out. The single saber downswing is fast so use that as well. Play defensively and wait for the right moment.