I think it should say "by spells or abilities," since I think they like to leave it being countered by the rules open.
Interestingly, this could still be countered by Redirect, am I right?

I like it. It probably could be mono-blue, but maybe ismore interesting as not. It probably can't be costed as is; it's better than counterspell for GU, and it would probably have to be GUU or more. Perhaps make it a negate variant, then it's better than negate for GU instead of 1U, and fits better into the G philosophy. I suspect the decision would end up made depending on which spells development want to be very-hard-counterable.

Link: Yes, on both counts. It could have hexproof, shroud or split secnod instead of uncounterable if drugs wants to close that loophole; it seems hexproof might as well be used on spells instead of "can't be countered by spells or abilities" now the keyword exists (although it's confusing that it would mean a different thing on a non-creature spell and a creature spell).

Well, it is monoblue, as Last Word. And yes, Time Stop or Redirect will still counter this.