Urza, Lord High Artificer I wouldnt be shocked to see people make the swap for him over Sai, Master Thopterist, but Urza ought to see a bump as people include him in the deck
Our honest take: buy singles for a deck's core cards where you need specific pieces to function
Summon: Fenrir Summon: Fenrir is great in any green-leaning deck that treats sagas as value engines, especially if you can remove counters to re-trigger the same chapter, like with Garnet, Princess of Alexandria
Kardur, Doomscourge is the only Goad-like effect that affects those creatures, so playing against a haste-happy opponent can be trouble
This is card advantage already but you can get more spells later in the game after you've got the mana
Abilities like prowess and delirium benefit you when you cast instants and sorceries