User blog comment:Megames1/Against the Meta INVINCIBLE! Plus More!/@comment-5170841-20121004111425/@comment-89.80.9.19-20121005041941

Too long didn't read, but just saying: manamune was created way after the first heroes with energy system. In fact, I think that manamune is like one year old while the game is three.

It was invented cause tear of the godess was kinda useless (only 5% heroes was getting archangel back in the days) and some AD champs needed mana (i.e: Urgot, I do think that in fact manamune was created mostly for him).