Fun fact: hertha has one time drugged strade and put him in the freezer (turned off) for about two days with a corpse of one of her victims, all this purely because she was curious (and bored) about how far strade would go.
After that he never accepted anything that hertha got her hands on and every now and then he plans something against her but truth be told he created a monster who knows his greatest weaknesses lmao (he wont survive)
Honestly Yoki would be kinda excited. All her life shes dreamed of having siblings because poor lil girl just wants someone to play with that wont cry and run off after she bites them.
Hanz would sorta just be curious. He would be like "oh hell yeah cool sibling" and then immediately try to assert dominance and then make the sibling do everything for him (chores ect) he woukd sorta be a prick even to a sibling
And basil. Hmmm. Basil would just be more curious. He has no clue how to talk to people even if they are blood related 💀
Also to answer their favorite foods, ive said before that Yoki's is rabbit. Hanz would probably be like steak or something. Something barbecued since thats the only time Strade actually cooks good food. And Basils would probably be like yogurt or salad. Something small he can keep down
(Also have a little doodle I made of Ren finding a little gift on the doorstep from Yoki in the morning)