What does St. Nichiren himself say in their own writings?

"Since the Buddha of the Juryo chapter is revealed as the eternal Buddha, it follows
that the great bodisattvas such as Monju and Miroku and the great bodisattvas from
other realms are in fact disciples of Shakyamuni Buddha."
(MW vol 2, Ibid, pg 150)

 "All these beings are discples of Shakyamuni Buddha.  Since the various Buddhas themselves are emanations of Shakyamuni Buddha, it goes without saying that their disciples must be disciples of Shakyamuni.  And of course the various decties of the sun, moon and stars  who have dwelt in the world from countless ages in the past must likewise be disciples of Shakyamuni Buddha." (MW vol 2, Ibid, pg 152)

 "The Lotus Sutra is nothing other than a scripture that reveals that Shakyamuni
 Buddha attained enlightenment at a time even more distant than gohyaku-jintengo."
    (MW vol 2, Letter to the Priests of Seicho-ji, pg 268)

            "As it was stated later in the Lotus Sutra: "I,
            Sakyamuni, alone can save all the living beings."
            The only Buddha who can save us therefore, is the
            very Sakyamuni Buddha.  Sakyamuni never seems
            to have appointed two or three saviours; we do not
            have two fathers and two mothers, do we? Nichiren
            Daishonin, (Yorimoto Letter of Explaination, p.202,
            Noppa) Key Phrases from the Kanjin Honzon Sho,
            (True Object of Worship) ...

            "People can attain Buddhahood in two ways: By
            meeting the Buddha and hearing the Lotus Sutra, or
            by believing in the sutra even though they do not meet
            the Buddha."
            ...
            "The Juryo chapter reads: "The time is limitless and
            boundless -- a hundred, thousand, ten thousand,
            hundred thousand nayuta aeons -- since I in fact
            attained Buddhahood." Present within our lives is the
            Lord Shakyamuni who obtained the three enlightened
            properties of life before gohyaku-jintengo, the original
            Buddha since time without beginning."
            ...

---

            "You who are my disciples, take this to heart! The
            Bodhisattvas of the Earth were the first disciples of
            Lord Shakyamuni when he attained enlightenment in
            the remotest past, yet they were not faithful to him in
            India" (Major Writings of Nichiren Daishonin Vol. I. pp.
            45-83 )

            "I have heard that you are suffering from illness. Is
             this  true? The uncertainty of this world is such that
             even the healthy cannot remain forever, let alone those
             who are ill. Thoughtful persons should therefore prepare
             their minds for the life to come. Yet one cannot prepare
             his mind  for the next life by his own efforts alone. Only
             on the basis of the teachings of Shakyamuni Buddha, the
             original teacher of all living beings,  will he be able to do
             so." (Encouragement to a Sick PersonMajor Writings of
             Nichiren Daishonin, Vol. 6, page 19.) In 1277 (the third
             year of the Kenji ere) Nichiren Daishonin wrote a
             deposition on behalf of Shijo Nakatsukasa Yorimoto
            (the autograph no longer exists but TWO versions copied
            by Nikko still exist at the Omosu Hommonji (STN v.2,
            1346, 1360 notes):

            1)  an unrevised version compiled in 1278 (the first year
            of Koan) with the title "On the Dialogue with Ryuzo"  or
            RYUZO MONDO SHO.

            2)  a "revised version" copied in the fifth year of Showa
            (1316) when Nikko says he was seventy-one years of age.
            Since Nikko s colophon says that he copied this from a
          "revised  version" (saiji hon) it is probable that Nichiren
            Daishonin rewrote some of the passages some time after
            1278.

            Clearly by copying this version relatively late in his life
            Nikko regarded it as the more conclusive.

            Let's  look at an fascinating passage which reiterates the
            faith that Nichiren's disciples are to declare:

            "I believe it is preached in the HOKEKYO that His
            Reverence Nichiren Daishonin is the BODHISATTVA
            JOGYO, the messenger the Tathagata Shakya, Lord of the
            Three Worlds, Father and Mother of All Beings." (STN v.2
            1358 and note 1).  The capitalized part, the words THE
            BODHISATTVA JOGYO are in the revised edition from
            Nikko's old age.

            Clearly in the revised edition Nichiren Daishonin himself
            went to the trouble of adding the words "the Bodhisattva
            Jogyo" to the text.  Even if Nikko long after Nichiren's
            death added those words here and in the other revised
            sections, it shows how Nikko regarded Nichiren Daishonin.

            This is proof of how Nichiren Daishonin or, at the very
            least Nikko, saw his true identity. This identity, which
            sometimes modestly hid, was that of the Bodhisattva
            Jogyo, NOT that of the Buddha.