I actually recommend Assault Suit. It seems innocuous, but it works surprisingly well in a meta game full of sweepers. It grants Zurgo a buff, he can't attack you, but he still must attack every turn, even when under an opponent's control. So, not only will the Zurgo Commander damage continue to pile on, this also keeps his indestructible ability active, so he can basically never be destroyed by a sweeper that's not Rout or something. It allows for Commander damage kills in 3-4 person games pretty easily since it reduces the number of times you have to swing Zurgo significantly (because your opponents will have to do it for you).

I would remove Spellbook for Assault Suit. Spellbook is a card that does literally nothing to help you win. In fact, you could just add 1 Reliquary Tower to your mana base if you're concerned about having too many cards in hand (remove Radiant Fountain for it).

Fated Conflagration could easily become Wildfire, which would impact the game in a much more significant way.

I won't suggest you change the deck too much, but here's what I recommend changing:

Assault Suit, remove Spellbook (artifacts are easily destroyed and you can't win off this card)
Reliquary Tower, remove Radiant Fountain (Fountain is meh while Tower is a harder to destroy Spellbook)
Wildfire, remove Fated Conflagration (you seem to like destroying lands, what with the Armageddon and all, and you could ride this to victory in some cases, whereas Conflagration is just an over-cost burn spell that can't hit players).