Aether Revolt: mechanics

Prerelease of Aether Revolt in starts on January, 14 (paper Magic). Energy counters and Crew are the returning mechanics. Additionally, we will get two totally new:

• Improvise - a keyword ability that enables you to pay generic mana cost with the help of your artifacts. Each artifact you tap after you're done activating mana abilities pays for one generic mana. In other words, your spell will be cheaper if you tap artifact(s) while casting the spell. Improvise won't ever cover the colored mana portion of a mana cost.
  Tip: you can tap artifact creatures even if they have summoning sickness. 
• Revolt - an ability word that checks if any permanent you controlled left the battlefield this turn. It doesn't matter where that permanent went. A creature died or got exiled? Revolt. Your pernament was bounced? Revolt!