I believe that Pope Francis will initiate the great apostasy by teaching truths that are contrary to the views of many conservative Catholics:
1. the Church has the authority to ordain women (solely) to the deaconate
2. non-Catholic Christians, non-Christian believers, and non-believers can be saved without converting
There is nothing wrong with either of these teachings. The problem is that some conservative Catholics have decided that the common opinion of conservatives cannot be wrong. They consider that the correct answer to any theological question is the conservative answer. But when we look at Jesus’ teaching, we see that sometimes the right answer is liberal, other times moderate, other times conservative.
Many conservative Catholics will declare that Pope Francis is a heretic, and will break away from the Church as a result.
Then, during the reign of Pope Francis’ conservative successor (Pius 13), the Pope will teach truths that are antithetical to the views of liberal Catholics, resulting in another (larger) departure from the Church.