Those cards are Bothersome Quasit, Astral Dragon, and Loot Dispute
For those not in the know, these two siblings have been integral to countless moments in Magics story, and are some of the most mythic of characters in the story, albeit not quite as popular as the likes of Nicol Bolas
Obviously, that deck is a bit of an implementation against last years Blade Splicer into Hero of Bladehold Ones-and-Fives G/W
This mount can be unlocked early on, too, as it has no required level or quest involved
This can make a huge difference as some cards have a market price of double their actual buying price
The card gets interesting if youre running Sunforger, but most of the spells Im excited to cast with Sunforger are three or four mana, so the synergy isnt quite there