Shadow in the Warp
Enchantment
The first creature spell you cast each turn costs 
less to cast.
Whenever an opponent casts their first noncreature spell each turn, this enchantment deals 2 damage to that player.
The astropath collapsed, his empty eye sockets aglow. He spoke three words before falling lifeless to the ground: "They . . . are . . . coming!"
Kim Sokol
Rulings
Both the first and last abilities of Shadow in the Warp take into account spells cast before it was on the battlefield. For example, if an opponent cast a noncreature spell before it was on the battlefield, then casts a noncreature spell after it is put on the battlefield, Shadow in the Warp's second ability won't trigger because that is the second noncreature spell they've cast that turn.
(wotc • 2022-10-07)
Rulings
Both the first and last abilities of Shadow in the Warp take into account spells cast before it was on the battlefield. For example, if an opponent cast a noncreature spell before it was on the battlefield, then casts a noncreature spell after it is put on the battlefield, Shadow in the Warp's second ability won't trigger because that is the second noncreature spell they've cast that turn.
(wotc • 2022-10-07)