What Mortals are affected by the first ability?
All Mortals, anywhere in the realm.
If a Mortal with Deathrite dies, who gets the Deathrite ability?
The King's controller, since Deathrite triggers while the units are technically still in the realm.
What happens if a second King of the Realm enters play?
See 'Example - Two Kings of the Realm' in the codex.
If my opponent plays a Mortal with a Genesis ability and I have a King in play, who gets the Genesis ability?
The player with the King gets the benefit, since they control the Mortal as soon as it's in play.
Market
$1.50
Low
$1.00
Median
$2.00