The key thing to note here is that the ability is restricted based on power, not mana cost, meaning Alesha can cheat expensive creatures like Herald of Leshrac or Abyssal Horror into play for explosive early-game value
The card gets outclassed when you really push mana acceleration, but Im plenty happy having Wall of Blossoms alongside a lot of messed-up Vintage Cube cards, so it has value everywhere
Famished Worldsire (EOE) $9.23 This card is expensive, but its very potent
Aces Baseball Bat (WHO Surge foil $1) Same idea, two mana, three power, one to equip
Still, the fail case is two mana for a 2/2 flash with a useful creature type, and if you can find a way to make something die before you cast it, its going to give you some awesome value
Drawback 1: Dungeon Descent enters the battlefield tapped