Commander Marchesa, the Black Rose Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.) Other creatures you control have dethrone
There are already a ton of cards that do the same job as Starscape Cleric in this combo
It has been a very long time since Spitebellows and Jalum Tome were acceptable removal and card advantage, and similar weaknesses pervade the deck, down to the outright puzzling inclusion of cards like Tuktuk the Explorer and Beetleback Chief that don't interact with the gameplan at all
Once you have Sigarda protected with something like Swiftfoot Boots or Champion's Helm, you can use Sigarda to look at the top of your deck at any time you like
You set the price, condition, and shipping options yourself
This may be better than its forebear against WU decks (since there are rewards for playing lots of spirits and a higher density of playable spirits), but its still most likely a sideboard card