Fighting Alone
After receiving that plan, Rea immediately told Walker to lead their force back into the army to relieve them. She also grabbed the radio to learn about the entire situation and asked to be updated about it.
She had to make sure that the battle wasn't going to develop worse than this.
Of course, Walker was in charge of protecting Syk. Although she was a bit worried that Syk would be targeted, considering he was also a monster.
She had told the commander to spread the words to their current force about Syk and two King Class Monsters. So, when people tried to harm Syk, some or even many people would try to protect Syk.
Whether it was because killing Syk would incur the wrath of their benefactors or because harming him would be equal to their defeat, she only wanted him to be protected at all times.