While most spells arent going to need to cost 10 less you could always use this with X spells, much like you can with Magus Lucea Kane
Any time I get a Disney Lorcana assignment I can pretty much guarantee that I'll have that movie's soundtrack stuck in my head until I move on to the next card
It basically turns every land you play into Ancient Tomb for a turn while fixing your mana and really going off with fetch lands and multiple land drops
If an effect exiles Summon: Esper Maduin and then instructs you to return it to the battlefield, it remains face up in exile (unless that effect instructs you to put it onto the battlefield transformed, in which case it returns as Summon: Esper Maduin)
Good aggro decks are all about finding ways to properly skew the curve outs to your side
The main problem we have here is that this creature just doesnt really do it in modern Magic (I could see this being an uncommon these days!), and the rate wasnt even really good enough when it was first printed, either