It takes some skill to make a hybrid Agile methodology work successfully and anyone who would literally try to combine an Agile methodology with a Waterfall methodology to create a hybrid methodology is asking for failure. That’s not the way to do it.
Proponents of Agile blame Waterfall for creating projects that are not successful. The root causes of most Waterfall problems are the result of poorly-scoped, poorly-planned and poorly-executed projects created by untrained teams.
This flexibility allows them to easily reconsider a decision resulting from new information. In my experience, combining Waterfall and Agile project management methodologies into a hybrid approach to manage projects increases the ability of projects to rapidly manage changing customer, sponsor and other project priorities.