Why did aizen crash out against ichigo but become nonchalant again in tybw

Like bro was nonchalant all of bleach up until his fight against ichigo where he went full crashout and got sealed but then when we see him again at the end of the arrancar saga and in tybw hes nonchalant again, was he just showing his true feelings against ichigo because he was the only one who was on par or stronger than him or was he just mad or wgat