wagyu has a lot more fat in the cut and you don't want to over render it. a reverse sear is a great technique for really high marbling like a ribeye. I would only do this with 1" or thicker cut steaks:
1.Preheat oven to 275f
2.Place well seasoned, ROOM TEMPERATURE steaks on a rack over a baking tray. Just salt and pepper and don't be shy.
3.Put in oven and cook to an internal temp of
110-115f (mostly rare, but important) your preference of doneness doesn't matter here.*
4.Remove when at temp and rest for 10-15 minutes under foil
5.Preheat a cast iron skillet or heavy based pan to screamingly hot, no oil needed.
6.Sear steaks for one minute each side
7.Serve immediately, or you can get crazy and throw a big pat of butter in the pan at the last second and baste that sucker for a few extra seconds, then devour!
This will not be necessary but still fun, who doesn't like butter?*I'm extremely jealous and require photos of the end product Jon.
Edit for clarity. I have made some amendments to my instructions after talking with a cook that has more experience.
DO NOT over cook this or I will come and relieve you of your cooking duties!