Yeah Cressy is good in sun teams, as it solves many of its usual problems, such as dragons, Landorus and Terrakion. However i think Reflect is the best option in the last slot, to be able to deal with Ttar and Scizor at the same time. It's not like Scizor is a threat for Sun teams anyway, so HP Fire is not really needed imo.
Part of the OU QC team, message
me for a check!