Steroids don't just magically gain muscle and lose fat. Injecting test does improve lean tissue, but that's a different conversation. Almost any oral can be used for any phase of dieting. Some are better suited than others, but the point remains.
I've used msten for both bulking and cutting, and i have been very happy with the results in both cycles of dieting. I think msten is one of the better compounds on the market. One of my favorite stacks, actually, is msten + dzine. If you monitor your diet, don't go in to too high of a surplus, msten will enhance muscle gains over what you would accrue naturally. But, if you go too high in to a surplus, you'll gain fat. Obviously.