Crate of Entertainment killed. Finally I have a Pet Ritualist capable of doing that 
Kill time is same as that of Will O Wisp - Pet Cabalist
EDIT:
And… it is official. The build is more powerful than Will O Wisp and is more similar to my The Fluffy Squishy - Pet Conjurer
Callagadra killed at 9-10 mins and Ishtar is going in my Top 3 list.