Ever since Eric came to this country with Lina, his loyalty had been unstable. He disguised this fact very well in front of Lina, still pretending to be her capable assistant. However, once Lina decided to return to the country to search for her heir, his heart had changed.
Eric had long considered LAYNA to be his own company. Why else would he have worked so hard for Lina for so many years, treating Lina's concerns as his own concerns and the company's values as his own values?
All of this was because Lina had once said that she didn't have a child or an heir. When she got older, she would hand the management of her company over to her assistant.
Therefore, Eric had poured his mind and heart into becoming Lina's assistant. In reality, Lina also thought highly of him. Many important aspects of the company were solely his responsibility. This extension of trust and responsibility made Eric feel that she was cultivating him to become her successor.