Gatecrash: new mechanics, part 1/2

In one week time we will be pleased to take part in prelease event of Gatecrash. Thus, I decided to introduce you the new mechanics. Every guild have its special abillity. Like in Return to Ravnica we will have 5 guilds: Orzhov, Dimir, Gruul, Boros and Simic.

The Orzhov guild (WB): extort. Whenever you cast a spell, the extort abilities of permanents you control will trigger. As the trigger resolves, you'll be given the chance to pay  W or B . (All extort cards, regardless of color, let you pay either color). If you decide not to pay, nothing happens. But if you do have a spare mana to pay, each of your opponents will lose 1 life, and you'll gain that much life. Each trigger lets you pay up to one mana; you can't pump more mana into it.
 
The Boros guild (WR): battalion. Battalion is an ability word that marks a particular kind of triggered ability. A creature's battalion ability triggers when it and at least two other creatures attack. The bonus from battalion abilities varies from card to card, but the trigger is always the same.
Battalion abilities use the stack and can be responded to normally.

The Simic guild (UG): evolve. Evolve is a triggered ability that triggers whenever another creature enters the battlefield under your control. At the time that happens, you compare the new creature's power to the evolve creature's power and the new creature's toughness to the evolve creature's toughness. If either or both of those values is higher for the new creature, the ability triggers. It only triggers once for each creature that enters the battlefield, even if that creature's power and toughness are both higher. After the ability has gone on the stack and players have a chance to respond to it, it resolves. If the new creature still has a higher power and/or toughness, you'll put a +1/+1 counter on the evolve creature. If multiple creatures enter the battlefield at the same time—say, because they're tokens—evolve triggers separately for each, and the triggers resolve one by one.