If you want to Sav a low level Poké so it eventually becomes a perfect level 100, just make sure to enter all of the desired IVs and EVs, set the level to 5 or 1, set the evolution to its earliest stage, and then use something like the Shoddy Team Builder where you can type in a level 5 Riolu with 31-31-31-31-31-31 and 4-252-0-252-0-0 (for example) and it shows you immediate stats