It is capable of many things, ranging from the acquisition of effects which certain cards only hold when they're Summoned in an specific way (a simple example would be Traptrix Dionaea, which has an at Normal Summon and a different at Special Summon effects), or avoidance of penalties for being Summoned in other ways, like the typical card that must be destroyed or returned to hand at the end of turn for being Special Summoned, or the high leveled mon that is at its strongest when Tribute Summoned
If it is the only card Monster you control when summoned, it brings a Token out with it as well
Like most Magic: The Gathering cards, the value of Boon of the Wish-Giver depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Ikoria: Lair of Behemoths)
But heres the trick: since you know Birdcage is coming, you can build your deck to dodge its downside
(Unless Im missing something, theyre not imitating or forgeries of cards: They dont and arent meant to look like them
