In the Deep (Part 1)
After several hours spent studying the tower's control system, Lith and Solus had indeed found how to limit the flow of information to her brain so that she could use her Eyes form without frying her brain.
The problem was that such an option was only available when Solus assumed her tower form. Hence, she and Lith had worked hard to find a way that would make him shoulder half of her burden via their mind link.
It allowed Solus to double her brainpower and halve the side effects of the Eyes of Menadion. On top of that, now that Lith had finally developed a breathing technique that made use of his auxiliary cores, the stronger his deep violet core became, the faster the tower's power core regained its form and functions.
Soon after the events in Lightkeep, Lith had discovered that Accumulation provided to his mana core a negligible amount of world energy compared to what he needed to refine it further.