Why was he called ''bastard''?

[Giuseppe]

It is easy to quote on Google from the first apologetical site the following accusation by Jews against the Gospel Jesus:

In an especially rancorous exchange in the Gospel of John, “the Jews” retort to Jesus, “We’re not bastards!” (John 8:41). (“Bastards” captures the insulting tone better than the more polite translation, “illegitimate.”) The syntax of the assertion puts the emphasis on the “we,” and thus implies, “We’re not bastards—you are.”
The second-century anti-Christian polemicist Celsus relays a story that Mary was impregnated by a Roman soldier named Panthera. The Talmud contains a few cryptic allegations that Jesus was illegitimate, and a medieval Jewish story characterizes him as a child of adultery. For reasons that cannot be considered here, it is best to consider all of these as fabricated responses to the Christian claim that Jesus was born to a virgin.

But why was he called a 'bastard''?

If we read proto-Mark according to Gnostic lens, we may answer easily.

Jesus is called implicitly a ''bastard'' in Nazaret when he is accused to be nothing other than the ''carpenter'' and the ''son of Mary''.

The ''carpenter'' is the Demiurge, the bastard son of Sophia, who was imprisoned by 7 planetary archons after having produced - without need of a husband - the abort par excellence (the same Demiurge), i.e. Mary of Magdala who was exorcised by ''seven demons'' possessing her.

''Magdala'' allegorizes the tower, i.e. the prison where she was held prisoner.

Therefore the inhabitans of Nazaret -- real davidic descendants themselves -- are accusing Jesus of being not really of Nazaret, but born by a unknown father (just as the ''abort'' son of Sophia, the demiurge). In other words, they accuse him of being a 'bastard'.

In order to correct this view, the interpolator of Mark added the list of brothers and sisters for Jesus, so that Mary becomes now the legitimate mother of Jesus and distinct from Mary of Magdala, the Sophia who recognized his deliverer on the cross ''from a distance'', in the darkness of the demiurgical Creation.

Therefore this may cast light on the ''born from woman, born under the Law'' bit in Gal 4:4.

She is really Agar, the slave, herself an allegory of the lost Sophia enslaved by the Demiurge (the Law). The Gnostic Paul is saying so that Jesus appeared in the world under the human appearance of a slave of the Demiurge.

[Giuseppe]

It has recently been argued that the darkness that covered the land at the time of Jesus's crucifixion is an allusion not only to the darkness of the plagues of Exodus 10 or the darkness of mourning in Amos 8, but even to the primordial chaos of Genesis 1:2-3. This makes sense of the extent of not only the darkness motif but also its location “over the whole land” (Mark 15:33).

If Mary of Magdala recognized the true Son of God on the cross ''from a distance'', i.e. from the abyss where she (Sophia) was sunk with the Creation/Fall of the Demiurge, then the darkness allegorizes this same Creation: really a Fall provoked by an inferior god.

Therefore Mark 15:33 isn't saying that Jesus's death is inaugurating a new creation. At contrary, Mark 15:33 is saying allegorically that the same celestial crucifixion of the Son happened just before the creation of the material world, in the darkness emerged in the same instant of this creation, just as prof Robert Price had written:

It was part of the same theological transformation whereby the myth of the slaying of the Man of Light by the archons before the foundation of the world was rewritten as the historical crucifixion of a human being, Jesus Christ, at the hands of the Sanhedrin and the Roman procurator. As the extraction and seeding of the spiritual photons of the Son of Man had enlivened the new-made earth, so the blood of Jesus was now said to redeem the souls of humanity.

(The Amazing Colossal Apostle, p. 82, my bold)

Mark 15:33 seems to be really the signature of the original Gnostic author of the Gospel.