State-based actions happen before a player receives priority
And lets not forget that its a 5/5 flyer with haste for just five mana
This feeling and flavor are exactly what the Planechase game mode was created to convey in 2009, where players are now battling on a plane, represented by a plane card with special rules
Important to note that the system is still in beta testing, so this is probably going to be different in the future
Number 22 Language English Legal Formats Commander, Legacy, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Modern, Pauper, Pioneer, Standard, Timeless Rulings (7/26/2024) If a spell has in its mana cost, use the value chosen for X to determine that spell's mana value
Being a Leyline, this Enchantment has the added benefit of starting a game on the battlefield if it's in your opening hand