Mind Plus

Mind Plus, also known as Magic Source and Mag Up, is a recurring item in the series. It permanently increases a character's Magic stat (Intelligence in the original Final Fantasy) by +1, and is thus a very rare item in the games it appears in.

Final Fantasy
Mind Plus only appears in the Dawn of Souls and 20th Anniversary versions and can only be found in the optional dungeons such as Whisperwind Cove and Lifespring Grotto.

Final Fantasy VII
Magic Source can only be found in Junon, and afterwards only by morphing Unknown 3 or 8 Eyes.

Final Fantasy VIII
Mag Up can be stolen from NORG Pod (Left Pod), and afterwards, can only be gotten through refining 10 Royal Crowns into 1 Mag Up.