Boushiya used a term of 化現-kegen, which means something like in order to save humans, gods take in some kind of form to do the deed needed to be done in the 2nd bubble. It has a deep meaning so I note it down here.
If our human's feelings got too strong then it'd become hard for us to take form.That is not just limited to us, but also to the Abyssal ships.The so very heavy wishes can not be grantedIt's the same reason why those like Nagato are hard to be dropped compared to others.
Drop is the provided reading for "invoked", as in invoking a god to possesses someone.From then on, until now, as people's feelings get deep and complicatedly more and more piled up