Nice sleuthing, Plot.. (some of us are spotting the red herring, you’re next door already prepping sashimi…)
I noticed I could only find this in wiki pages that Walter Bernhard became Niklaus Mikaelson. (About as appealing as the Gabriel>became Mathias>Became Dracula theory)
Interestingly, given Mikael’s children (Niklaus included) carry the Mikaelson name, one assumes this is due to the children literally being ‘Mikael’s sons(/daughters)’..
PS: They need to remake LoI.