Cursed Mirror falls into this 'temp clone' territory, but prooves that one turn is often good enough
It can be very hard to kill and it can offer you card quality all the while being a very good creature with no downside
Although the spell wont be countered if the targeted artifact or enchantment goes away before resolution, you still wont get the counters because the condition of getting them is that the permanent is exiled in this way. I think I like the card more because you have to have a creature on the battlefield in order to cast it, a thumb in the eye of creatureless or low-creature decks
8.8/10$0.30 Eviscerator's Insight Instant As an additional cost to cast this spell, sacrifice an artifact or creature
There are efficient, colorless cards like The Underworld Cookbook that can enable Emrakul, and you can even tutor for them from your sideboard with Karn, the Great Creator
Prevent all damage that would be dealt to those permanents this turn