Blue ability-messer

[Slay]

Blue card
U
Instant
Choose one - You control target activated or triggered ability, or target opponent controls target activated or triggered ability.

I know, it's an instant win with Phage + reanimation. I don't care. It would be pretty neat to steal a fetch. What do you think?
-Slay

[Limbo]

This is Stifle on steroids, and thus its casting cost is too low I think.

Besides that, I really like it.

[Jacques]

Not nessicarily.  There will be triggered effects you just want to stop such as an Oblivion Stone or a Mindslicer.  I definitely like the power this has, though there are some rule complications.  Any reanimation that says target anything from your graveyard for instance.