Of course, he chose to add an extra eye. Before that, he needed to modify the spot between his eyebrows to make a place for the Demon Eye transplant.
At the same time, after the modification was complete, he would need to set up a layer of protection to avoid being influenced by the Evil God's power. This layer of protection would also need to be easily controllable, so that when Isaac became powerful enough, he could lure the Evil God over!
There was a lot to do, but not much he could actually do. There were just too many Demon Eye abilities, and Isaac thought all of them were pretty good...
Things like the Petrifying Demon Eye, the Gravity Demon Eye, the Freezing Demon Eye, the Transforming Demon Eye, the Hypnotic Demon Eye, the Pregnancy Demon Eye, the Gender Transformation Demon Eye...
They were all pretty decent Demon Eyes!
Their combat potential was off the charts!
So...
'Damn it, more choices?!'
