Paracelus Phase 2

[Received]

I don't think Paracelus is scaling correctly in his second phase since I was playing on my Level 2 twink and I couldn't inflict any damage upon him.

I've had no trouble with any of the other bosses or Paracelus phase 1 so this seems a little out of place even for the final boss. It has become incredibly frustrating since I've wasted numerous energy kits due to this.

So, is it intentional that Paracelus behaves in this way?

Thanks

Edit: Ultimately, if this event is truly for all levels surely I should be able to kill all the bosses?