Attention
Both Devils, Kaeldur and Tyrant were far from ordinary Originals at the Deux rank. They were much stronger and faster than ordinary Deux-rank Originals. At the same time, they had more experience than God-like existences because they had been on par with Gods in the past.
In their prime, the two Devils had fought by Damian's side against countless powerful opponents. Thus, defeating someone at the Deux rank was supposed to be an easy task for them.
However, that was not the case against all kinds of Originals even if they were in possession of powers that could hardly be countered by beings at the Deux rank.
That was why it shouldn't have been a problem for Kaeldur and Tyrant to defeat Michael Ignis by themself, let alone in a four versus one battle with someone like Nial by their side who made use of his tremendous powers and even Broken Runic Armaments.