Whenever Cass or another creature you control dies, if it was enchanted or equipped, return any number of Aura cards that were attached to it from your graveyard to the battlefield attached to target creature, then attach any number of Equipment that were attached to it to that creature.
You can’t return Aura cards that can’t legally be attached to the target creature. For example, if the target creature has protection from red, you can’t return Grim Reaper’s Sprint to the battlefield with Cass’s last ability.