what turn do your games end at? we're usually around 7-9 which is why I was wondering about the density of targets. The fetch triggers are cute but I'm I guess wondering if it's broadly okay as well as narrowly fantastic. I'll slot it in and see what happens!
Just run an excessive number of Brainstorms so that people can shuffle them away.
I'd say usually it doesn't sit dead in hand the entire game. It's a high-variance card though. Sometimes you do hit their fetch and it doesn't even really affect the course of the game. Sometimes Stifle wins in scenarios where no other card can. It's not really a grand slam card, but my recommendation would be just to try it and see if you like it. My playgroup had a lot of Legacy players who likely overvalued it, and maybe some playgroups won't really want it at all.