Sheyan had endured quite a bit of suffering in order to save Pokan. He even had to use 'Gloryheal' before he managed to escape successfully. And even then, he was left with less than half his HP.
The first reason was because the 'Spiritual Storm' was abnormally powerful. If Pokan was not protected by the barrier, and his HP was not close to being full because he was guarded by the Rock Elemental previously, he would have died in the storm.
The second reason was because more than a dozen elite Violent Beasts had skillfully circumvented the area of effect of the 'Spiritual Storm' to chase after Sheyan. The rest of the Violent Beasts were also enraged, so as soon as the 'Spiritual Storm' ended, they formed the second group in pursuit.
Under such circumstances, Sheyan and Aldaris had no intention of sticking around, let alone fighting back. Not that they did not want to, but they simply did not dare to.