Armando reveals to Izdahl a far-reaching decision that had been made decades ago in The Architect’s Guardian, Chapter 30. Here’s a portion:
Izdahl sighed, feeling overall contentment but still wishing that his doubts could go away. He truly hoped that the decisions made decades ago by their families would not take away their happiness. Nitelge grew up with the understanding of just how much they were connected to the Shield. Humans rarely had the same level of requirement. So few were intricately entwined with it. Why was it that his lover, a human who completely had his heart, had been required to make such a great sacrifice? Even most Nitelge would never have to deal with this kind of burden.