Mechanicus: Unlock False God Achievement (Kill the C'tan)

I bought the relatively new PC game "Mechanicus" last week and played it every day since. If you like turn-based strategy games and 40k you should definitively give it a try.

I completed it two times, but there was an achievement which eluded me until now. I mean the "False God" achievement. Here is how you can unlock it: 

Press Spacebar in the mission select screen to enter the noosphere to make Tiresias visible and his missions selectable.

You collect information about a tesseract vault in six different missions and in the seventh mission, you can fight the C'tan eventually.

The unfolding fight is pretty easy. The C'tan shard has only 120 life and no shields. 

Piece of cake.

Besides unlocking the achievement you also get a new canticle!

Defeating the C'tan and doing all the missions before that was not hard, but to find Tiresias in the first place was the real challenge.

Why am I telling you all this? Well, I couldn't find a guide to get it and damn you GW for all your licenced games, because this one led to a rather spontaneous buy:

Skitarii will be my next Kill Team (at least)!