Aside from being apart from Daisy and the fact that he was in the den of the enemy where he was likely passing some of the people involved in his family's murders every day, Rukelion didn't mind being in the army much. He had simply switched from one daily routine to another.
Downtime was the worst because he didn't have anything he wanted to do. He spent his first week exploring the compound and trying to get more of a feel for the place since that information might come in handy later but not much else.
He couldn't joke around with the young men in his squad considering what he was here for. He was polite to them but would go no further. It didn't seem likely he would be able to get any of them on his side at this point anyway. He needed a situation that bred loyalty, such as the chance to save someone's life, to make that happen.