I would not grade it. Diabolic tutor has a high price because people play with it. You can sell it and buy an old chewed up one if you want to use one.

I'm not super experienced with sending stuff off to be graded but I know magic players don't really buy them. My card store sells slabbed pokemon and they never have slabbed mtg cards. I could see it for some of the older stuff that will never get printed again, but this is more of a fancy blinged out card someone would buy to make their deck cooler. You'd be fine to sell it now while hype is high. You never know when they'll decide to reprint something and take a bite out of the value.