If you control no creatures other than Joo Dee and no artifacts as the ability resolves, you'll need to sacrifice either Joo Dee or the token copy
But still, it makes a creature gain double-strike, and thats wait, they have to have two counters before theyre legally allowed to hit someone twice instead of just once
Youre looking to combine goblin payoffs with cheap disposable artifacts here, so include all the usual goblin lords and cards like Skullclamp, Prized Statue, and Ichor Wellspring
Festival sticks around permanently, however, with the trade-off that your spells damage you when you cast them
The counters are auxiliary to its primary purpose, which is to copy spells, but counter doublers like Hardened Scales and counter manipulators like Goldberry, River-Daughter give you far more control over what you copy