He did, lol. Don't bother doing anything with 2* and under stones, just sell them. You can try to powerup rare 3* stones and hope for an evolution, but the chance is very low; otherwise sell them too. Power all 4* stones to +15, even the useless ones because you need them to make unique stones. Don't worry about not having many 4* stones, you'll get a good supply of them once you're able to do the expert stone match. Expert stone match drop rates are around 75% for 3*, and 25% for 4*, no 1*/2* junk. Also, it's a good idea to hold back on powering up stones until a powerup discount event comes. These usually come around every 1-2 months.