Since no one has ever done a Sirzechs why not I do one instead.

So Sirzechs has heard from your confrontation with Riser when he came to the occult research club to see rias talking about their marriage where you unironically punched riser in the face since you saw what was happening to rias making her feel not like herself. So you were told about the forced marriage by kiba and you challenged riser when rias mentioned about the Rating games that will determine their results and riser accepted the challenge and accepted your challenge if your not either gonna back down or be the last one standing. So since that you wanted to see who even made this forced arrangement in the first place so by without permission sneaked into rias office to see if she had any other relationships with let's say a family member, and you found it. So you picked to either confront her older brother or her father but you picked brother since you were afraid what would her father look like and what he will do to you. So you set up the arrangement to meet up with Sirzechs since he said he won't be busy, but you thought it would be easy but in the inside you were scared on what will he say to you.