Board Thread:General Discussion/@comment-33648120-20171114133756/@comment-31661832-20171114160225

Yeah, as these two stated, the only way to get the Androids to 20 is raising another at SA 10 and awakening it all the way to LR or using Elder Kais. Personally I'd recommend raising the second copy, considering the Androids are so easy to pull from friend summons.

Other LRs, like SS Goku can technically be farmed by other cards (so you can farm the SA to 20 without getting a second copy) but the percentages are so ridiculously low that I wouldn't recommend it (it's like a 2% chance to raise SA of LR using a UR).