Answer: - Markandeya Puran and Shrimad Devi Bhagavata Purana explicitly prove that Brahma is Rajgun (Rajas), Vishnu is Satgun (Sattva) and Shakar is Tamgun (Tamas)
1. It is stated in Shri Markandeya Puran (Sachitra Mota Type, published from Gita Press Gorakhpur) on Page 123 that Rajgun Brahma, Satgun Vishnu and Tamgun Shankar, these three are the main powers of Brahm; these three are the three gods. These three only are the Gunas.
2. In Shrimad Devi Bhagavata Mahapuran, Sanskrit and Hindi translation (published from Shri Venkateshwar Press Bombay), in Third Skand, Chapter 5 Verse 8, it is written that God Shankar said, “Oh Mother! If you are kind to us, then why did you endow me with Tamogun, Brahma with Rajogun and Vishnu with Satogun?
It has been proved from the abovementioned evidence that Rajgun is Brahma ji, Satgun is Vishnu ji and Tamgun is Shankar ji.