Once he was aboveground Eric immediately set on his path towards the Assassin's Tower, he was going to make sure that he dealt with his backyard base first.
After all, if things had proceeded as he expected, and especially according to the instructions he had left, there was bound to be unrest in there.
Once he had dealt with the things in his own courtyard he could actually proceed and deal with the matters of the world.
With the help of the World Devouring Wrom, despite its exhorbitant price, he was even more assured of his success in dealing with any surprises that might pop up.
Not to mention that once his controlled Avatar was able to fully take control of its physical body, he would another extra powerful backer.
In fact, with the World Devouring Worm and Earth's Core both working for him, he was even more cofident on dealing with those superpowers in the outer world.
