The big reason why Mono Blue Spirits has fallen off in recent times is that it does not have a great matchup with two of the best decks in the format Rakdos Midrange and Rakdos Sacrifice
is an interesting card with another returning mechanic from Future Sight and only the second card with fortify as an ability, Darksteel Garrison being the other
What's important to understand is the difference between a card's raw power and how readily exploitable it is
Thats a good mix of stuff already, but it also gives you extra life whenever it takes damage, equal to that damage
What beats lifegain (know your weaknesses) Lifegains Achilles heel is that a high life total is only worth something if the game is decided by life totals and several strategies simply ignore it: Commander damage 21 points from a single commander kills you regardless of your life total
(If they had done the same in FCA, everything the same rarity, it would have been 128 packs for a specific foil.) I wanted to take this a step further, since they made these much more common than the Final Fantasy bonus sheet