El means Power.

In the apocryphal Gospel of Peter, Jesus's words from the cross are strangely, "my power, my power, why have you abandoned me?" This phrasing, instead of "my God, my God," has puzzled commentators and lead some to speculate on the mystic or Gnostic nature of the exclamation.
Justin Martyr refers to El meaning Power.
Epiphanius accepts that El means "power" in discussing a heretical Judaic sect called the Ossaeans (Panarion 2.19.2.1)
The Ossaeans also had a doctrine of Christ as a giant (Panarion 2.19.4.1).

Also the Gospel of Peter presents the crucified Jesus as feeling no pain, which led it to be condemned. The Odes of Solomon also attest to a tradition that Jesus felt no pain on the cross. They also attest to the tradition that Mary felt no pain in labor. Epiphanius also agrees with this in responding to the Ebionite sect that considered Jesus a mere man (Panarion 2.30.19.4).

August 11 2021: Note in Acts, Simon Magus is hailed as "the great power of God," or perhaps, "the Great Power, being God." Possibly "the Great Power" here was the word El--perhaps reflecting colloquial usage? I really don't know. Justin Martyr came from Samaria. Maybe that connection means something; maybe it means nothing. 

Early Influence of Acts on Heretical Baptism Narrative?

But the beginning of their Gospel is, “It came to pass in the days

of Herod, king of Judaea, < in the high-priesthood of Caiaphas >, that

< a certain > man, John < by name >, came baptizing with the baptism

of repentance in the river Jordan, and he was said to be of the lineage of

Aaron the priest, the son of Zacharias and Elizabeth, and all went out unto

him.”26And after saying a good deal it adds, “When the people had

been baptized Jesus came also and was baptized of John. And as he came

up out of the water the heavens were opened, and he saw the Holy Spirit

in the form of a dove which descended and entered into him. And (there

came) a voice from heaven saying, Thou art my beloved Son, in thee I am

well pleased,27 and again, This day have I begotten thee.28 And straightway

a great light shone round about the place.29 Seeing this,” it says, “John said

unto him, Who art thou, Lord?30 And again (there came) a voice to him

from heaven, This is my beloved Son, in whom I am well pleased.31 (8)

And then,” it says, “John fell down before him and said, I pray thee, Lord,

do thou baptize me. But he forbade him saying, Let it alone, for thus it is

meet that all be fulfi lled.”32

Epiphanius, Panarion 19.13.6-7, Frank Williams 142.

depending on when this was written, it could be early attestation for Acts!

Also, why is John experiencing what Paul does in Acts? Is John a good guy or a bad guy?

New thought, Aug. 11th 2021: The Clementine Homilies, in a few sections, portray Paul negatively through the guise of Simon Magus. The Homilies also claims that Simon was originally a student of John the Baptist, albeit a hubristic student. If both this heterodox gospel and these sections of the Clementine Homilies originally came from an Ebionite source, then it could help explain this strange insertion of words from Acts 9 into Christ's baptism narrative. Perhaps John the Baptist is also a negative cipher for Paul? Or perhaps this source wants to connect John, Paul, and Simon as anti-Christ figures? 

Perhaps this baptism narrative is a "put-down" of John? Perhaps it reflects the Homilies' syzygus theory where error precedes truth--here John would represent error and Christ truth, of course. 

If there is a connection between the Gospel of the Hebrews and the Clementine Homilies, then we have here a bit of reconstruction of the historical thinking of a particular lost Christian community.