Three hours later, Eldrian could merge the fire and water without using all his focus. In this effort, he had truly missed Two's help.
Handing some of the processing to another was such a wonderful cheat that Eldrian hadn't realized how much he always relied on it. Sure, he had learned of his reliance during all the fights since. But this really hammered home how reliant he had been on Two in other regards.
Eldrian also realized that it was impossible to split his focus as he was trying currently. His attention would always be pulled towards where he was failing, and in so doing, whatever lost some focus would fail too. Leading to a loop of things becoming worse and worse until the elements canceled one another. The more tired he was, the faster this happened.