I’m just wondering about baron Gieze and when did he show them the white wolf can anyone...

Can't remember the chapter but it was most likely when he was still engaged to Ivona. So in fact she was the one who summoned the beast and he took the credit that's why now he's panicking because he can't do that without Ivona

I'm not sure if he really showed them. I think it's from the past Yvona (before she died) when she was still 'worked' under him secretly. Gieze don't really have powers. He only used Yvona because past her had a feeling for him and he toyed with it for his benefits.