As I have written in my annotation to "Shree Skanda-Purana" (link), The Stories about Shreemati MahaLakshmi-Devi and Bhagavan Shree Vishnu can be found even in non-Vaishnava Khandas of The Purana.
For example, MahEshvara Khanda definitely belongs to Shaiva Siddhanta, but there is a story about Bhagavan Shree Narayana and Ekadashi out of blue in Chapter 42 of MahEshvara Khanda.
The Chapter is unique by itself, because it dwells simultaneously on:
1. Ekadashi Siddhanta
2. Mantra Siddhanta
3. Maya Siddhanta
4. Deha Dhyasa and Avidya Siddhanta
जागर (jAgara) means "to be awake" in Sanskrit, but when the Ekadashi implied "Jagara" means Jagara-Rite = "being vigil all night long during Ekadashi".
The distinctive part of "Shree Skanda-Purana" is the emphasis on 25 Angas of Ekadashi, very interesting notion.
Then another prominent feature of this Chapter of "Shree Skanda-Purana" is the mentioning of 2 Orthodox Mantras of Shree MahaLakshmi Sampradaya (also know as Shree Sampradaya or Shree Ramanuja Sampradaya).
