Outpost Siege

• WWizards of the Coast2014-11-24
  Official Ruling
  Each of the last two abilities is linked to the first ability. They each refer only to the choice made as a result of the first ability. If a permanent enters the battlefield as a copy of one of the Sieges, its controller will make a new choice for that Siege. Which ability the copy has won't depend on the choice made for the original permanent.
• WWizards of the Coast2014-11-24
  Official Ruling
  The card exiled by the "Khans" ability is exiled face up. Playing a card exiled with the "Khans" ability follows the normal rules for playing the card. You must pay its costs, and you must follow all applicable timing rules. For example, if it's a creature card, you can cast it only during your main phase while the stack is empty.
• WWizards of the Coast2014-11-24
  Official Ruling
  The words "Khans" and "Dragons" are anchor words, connecting your choice to the appropriate ability. Anchor words are a new rules concept. "[Anchor word] — [Ability]" means "As long as you chose [anchor word] as this permanent entered the battlefield, this permanent has [ability]." Notably, the anchor word "Dragons" has no connection to the creature type Dragon.
• WWizards of the Coast2014-11-24
  Official Ruling
  Each Siege will have one of the two listed abilities, depending on your choice as it enters the battlefield.
• WWizards of the Coast2014-11-24
  Official Ruling
  If you exile a land card using the "Khans" ability, you may play that land only if you have any available land plays. Normally, this means you can play the land only if you haven't played a land yet that turn.
• WWizards of the Coast2014-11-24
  Official Ruling
  If a noncreature card is manifested and then leaves the battlefield while face down, the "Dragons" ability will trigger.

Rulings via Scryfall