That alone is decent value, but splice onto instant or sorcery lets you sneak this effect onto all kinds of spells mid-combat or at end step
It does not provide any help other than negotiation, so its versatility is very low, and in the first place, negotiation decks aim for semi-guaranteed success by setting the difficulty level to 0 based on stylish outfits, not by increasing ability values like this card
A bundle containing all four Commander decks is also available
(2019-08-23) If the copied creature is copying something else (for example, if Volrath, the Shapestealer is having its own shape stolen by Hate Mirage), then the token enters the battlefield as whatever that creature copied
Your deck, predictable, consists of a lot of dragons and they hit hard