So, you want to increase your attack, defense, and speed, eh? Well, you've came to the right place! Here's how you can make your puny Robot Master into a force to be reckoned with!

To begin, go to your Robots and give your strongest RM that you currently have and give them either Attack/Defense/Speed Swap (Depending on which stat you need increased for you other RM). Then, go to the Into Field with your strongest RM and the RM that needs stat increasing. Use the swapping move on one of the Mets, swap over to the other RM. Once you kill the Met with the high stats, which isn't all that strong even with the newly found power, your RM will get stronger than it would if it were to kill an average Met (For instance, killing a Met with default stats will give you +1, while a Met with 9999 of a stat will give +50).

And, there you have it! If you have anything to add on to this strategy, please let me know, so I can make this an even better strategy than what it already is.