This clearly shows his realization of what an "ignorant being filled with base (evil) passions" (bonno gu soku no bombu) that he was. Further, in Article Two of the Tannisho, the Venerable Master is quoted as saying:

But since I am incapable of any practice whatsoever, hell will definitely be my dwelling...

Here the Venerable Master confesses that because he is so filled with evil, no matter how diligently he tries to do good, there is nowhere for him to go other than hell. It was from such a deeply self-reflective position that he religiously realized what he really is. This is, of course, just the Venerable Master's subjective evaluation of himself; from his conduct, all those around him considered him to be the incarnation of a bodhisattva.

As most people know, the Tannisho is not a work that the Venerable Master wrote himself. The author is considered to be Yuien-bo. Accordingly, some scholars have put forth the thesis that the position, "the evil person is the true object (of Amida's salvation)," is not something developed by the Venerable Master. That is, however, absolutely not the case. First of all, as you must also know, the first ten articles of the Tannisho are direct quotations from the Venerable Master. Further, in the General Preface of the Kyogyoshinsho, the Venerable Master wrote:

...Out of compassion, the World’s Hero sought in particular to benefit those who
committed (the five) deadly evils, the abusers of the Right Dharma and the Issendai.

As can be determined by this, the Buddha's great compassion extends even to those who have committed, or are:

• "(the five) deadly evils," which are: killing your father, killing your mother, killing an arhat, shedding the blood of a Buddha and creating dissension in the sangha.
• “abusers of the Right Dharma,” who are those who slander the Dharma,
• Issendai (Sanskrit, icchantikas), who have not had the opportunity to hear the teaching of Buddha-dharma.

Further, in the Chapter on Faith in the Kyogyoshinsho, the Venerable Master referred to those who commit the "five deadly evils," "abusers of the Dharma" and Issendais, as: "...(the) three types of beings who are difficult to save and who have the three kinds of illnesses difficult to cure." He then quotes a long passage from the Nehan-gyo (Nirvana Sutra) and comments on that passage, emphasizing that even these "difficult-to-save beings" are within the salvation of the Primal Vow. These are the places in his Kyogyoshinsho where we can see how the Venerable Master explained his position of "the evil person is the true object (of Amida's salvation)."