Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
I think this build is pretty effective with Bloodrazor. I tried it once in Blitzcrank One-For-All and did very well. I tried this in a Pantheon One-For-All and also did well. I then tried this build on Irelia in normals and worked. The clears are strong and with the right champion, the ganks can be too. (Blitz, Irelia)
What do I do?
Early Game - Farm more, but also gank.
Mid Game - Look for 1v1s and farm, split-push if possible
Late-Game Find picks, split-push, objectives.