That may not seem very powerful, but Sanctum Weaver is often the reason you can play all the cards you draw
You'll want to keep him as safe as possible with Bodyguards, Locations, and characters that grant him Ward or Evasive because if your opponent can't get rid of him quickly, you can run away with the game.
Sunpearl Kirin is one of those cards that just came out of nowhere and immediately found a spot in most formats
It also plays well with sacrifice outlets to trigger Nevinyrrals wrath and provide another means of triggering the enters ability
Its worth noting that this can trigger Up the Beanstalk even when cast for three, so it could see play alongside Rides End for that reason
With Atarka on the field, doubling damage and making blocking tricky, you can end most games on the spot