If you want to make a creature lose all abilities, you need to give it a new size as well - otherwise Tarmogoyf and Crusader of Odric don't know what to do. That'd be fine on this card: it'd be like Lignify with the interesting counter-them-all trigger.

Hmmm...So, the creature becomes a 1/2? Or should it be just 2/2 (make it a morph more or less.)

I think 2/2 is a good size. Blue shouldn't be outright crippling opponents' creatures, just weakening them. Kind of like why Rapid Hybridization makes a 3/3.

Hows the new version?

Looks nifty. I'd play it.

Cool card, I like it a lot. if it was in a regular set, though, it would probably be rare, or at least uncommon, since countering abilities doesn't happen all that often.

The ability should be worded, "When Chain of Impairment enters the battlefield, counter all activated and triggered abilities generated by enchanted creature." or "When Chain of Impairment enters the battlefield, counter all activated and triggered abilities for which enchanted creature is the source." or something like that. I had to check the comp rules to come up with a template for this one, because this effect is pretty unique!

I rethunk it a bit, and this is the best wording I could come up with.

When ~ enters the battlefield counter all activated and triggered abilities of the enchanted permanent.