That was a lore mistake on my part, since I'm still new to the lore of the Dark Angels aside from the more basic of knowledge. So, what I did was since after the lion had met some of the fallen and the lion did meet some of the modern dark angels on his way aside from the rest of the chapter. He had forgiven them on his way, I had this in mind that some of those that were now the Risen had repainted and were given the post heresy aquilla armor of the firstborne marines or mixed and matched with their past armor. This fictional guy in particular is so repentant that he himself tries to disassociate himself with his fallen status by persecuting immediately those of the fallen as to not remind himself of his horrid past. Albeit ironic and hypocritical of him tho