The capital is plagued with some disease and the civilians are suffering but he is "sick" in bed despite not even producing a single batch of medicinal herb. He is apparently the most renown Summoner in the capital so he should be able to do what Ivona has accomplished... It isn't too difficult to figure out what is going on so I think the Princess is definitely aware of the situation and made her move to expose him so that the Royal Family can proceed to ask Ivona for help and finally save the capital cuz those statues aren't gunna do sh*t.
Well there goes my theory that Seherz is the final antogonist. Unless she's been careful to hide her identity when working with them and this is her way of forcing them to work harder before she ultimately throws them away.