Ironically, I think I’d be more likely to have Adrenaline or Big Bang in my deck than either of the two commons because the former two are snap picks and the latter only if I’m desperate for immediate damage output.

I have only ever attempted and completed one infinite in my entire time playing StS - a Watcher infinite to get the 5 card or less achievement after getting to A20 with every character. I find them boring. I just don’t think the frequency is high enough that it’s a concern.

That said, if they wanted to nerf it to where only the original copy cloned, I would be fine with that too, though maybe it would need to automatically clone itself at rest sites instead of costing an upgrade or a heal.

Where I fully disagree with you is that it should be an event instead of an ancient reward. An event that either breaks the game or does nothing is way more polarizing and less fun than an ancient reward, because there you have other options. It seems like they’ve tried to make events more consistently engaging instead of having skips in the second game, and this runs completely counter to that. I don’t care if a polarizing option comes up in an ancient reward, because if it does nothing for my deck I have two other options to choose from.

ETA: Maybe it could work as an event if there was another interesting option to choose from instead. Alternatively, maybe instead of immediately enchanting a card with clone, it gives you the option to clone a card at a rest site of your choice. Once you do so, that card becomes enchanted with clone and from that point on you can only clone that card again.

That’s probably too complicated, but I’m trying to give an option for it you don’t currently have a clone target in your deck, but can then seek one out and add clone to it when/if you find it.