Nightwing
Junior Commander
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- Joined
- Jun 8, 2016
- Messages
- 306
Exactly this, if it was a LadyDevimon it'd be too obvious.Presumably, if SkullKnightmon is Tailmon it's precisely because they're two Digimon who've never been connected before, as they can hint at the reveal in advance to allow the twist make sense, while also leaving it nebulous enough that it isn't a foregone conclusion that we've known was coming since Angemon's egg was stolen.
It helps that SkullKnightmon works into the Black Knight character archetype almost perfectly lol.

Black Knight - TV Tropes
An enigmatic warrior, clad head to toe in armor black as night, which he is never seen without. Usually ridiculously powerful, he is feared by all who know of him. Wielding a sword, speaking in a low monotone or sinister growl, and looking …
I usually don't like using TV Tropes as a source for anything, but I don't expect everyone to know about the Black Knight archetype off the top of their heads lol.
It helps that they've threaded hints throughout the series though. Besides the direct connections to Kari, we've also seen both SkullKnightmon and DarkKnightmon use a bow and arrow, Angewomon's signature weapon, and one key line of dialogue for them was mentioning something about corrupting light to darkness and hope to despair when trying to corrupt Patamon's egg. Whether it's DarkMaildramon or SkullKnightmon, you can interpret that line as saying the Holy Digimon of Light was already corrupted by that point in time.
All that and the things Shotguner's already mentioned is a pretty good amount of evidence for the theory, I feel. I'll stop here though, since there's a difference between commenting on an Episode PV and discussing a theory lol.