An experiment. Now, this is all in dreamworld, of course, but when I was younger, I got my hands on a really old manuscript that had some information about the 'mother of all monsters,' which I thought was...well, some higher-being of monsters. Bigger than what Shabranigdo is there. So I manipulated the dragon slave spell, used the description in the manuscript to create the chant, add some heavy spellwork schematics and...there goes the Giga Slave.
A friend of mine had a vision about it saying the spell can destroy the world. I believed her. Then I got proof of it, thanks to another friend.
Then I accessed the Claire Bible, which is essentially in this other dimension and it's literally the memories of the Aqualord and, welp, that's how I found out the 'mother of all monsters' is actually 'mother of everything' and 'chaos and nothingness' and the spell is her. It. Whatever.
AKA, it was an accident. Like most of my life, I guess.