The easiest way to obtain this achievement is using a exploit from the game. I know, doesn't seem very fair, but to be honest, if the game allows then I cannot say you can't use it. It's a flaw that until this moment hasn't been fixed it.

In the Versus Mode menu, just configure the Rite as the achievement demands. Put 5 on "CPU Strength" (1.), enable "Titan Stars" (2.) and then simple change from CPU to P2 (easier done if you have an extra control). The option "CPU Strength" will disappear, but to the game, that configuration shall persist (3.).

1.

2.

3.

Commence the Rite. Select six stars from your chose (or all 12, it doesn't really matter). Customize your teams.

Just keep the second player still and win the match. After that, the achievement "Master Conductor" shall pop up (if you don't have "Enlightened", this shall pop up as well).