Marcius's draconic wings retained the same features as before but the way the many pieces of wings were held together had reverted back to their original form. Instead of lightning energy holding together the pieces, it was now the previous telekinesis keeping the many metallic pieces in shape.
It was because Marcius did not wish to reveal his advantage over the elder too early. He had a lightning affinity spirit beast and the elder favored lightning runic attacks. This meant that there was a great possibility that elder Khalid's attacks would have next to no effect on his person. And if Marcius's draconic wings were seen in their upgraded form with blue steaks of lightning all over them, it would be akin to Marcius's revealing his advantage very early.
Thus, Marcius decided to change the wings' appearance back to its previous original form, for a little while.