To be honest Blackbeard is such a badass character, he is just eating pies, drinking beer, carrying flintlocks, having multiple devil fruits, this guy just screams last villain!

Ok so Blackbeard wears these odd rings in his hands, he wears 4 in inch hand but only 3 of them on each hand have gems on them (maybe he puts the devil fruit powers on the rings so that he is not effected by water). Again the number 3 shows up yet again.

Then we have Shanks who was given a scar by Blackbeard pre-Yami Yami no Mi Devil Fruit.
How the hell did Blackbeard get close enough to give Shanks 3 scars? Wait did I say 3 scars? The number 3 shows itself yet again!

Some of you guys might say “but John Blackbeard had a weapon that had claws and that could be the reason why Blackbeard gave Shanks a scar” but the thing is that weapon had 4 claws and Shanks has only 3 scars.
Now let’s take a look at my actual theory. My theory is that Blackbeard has 3 souls. I believe that he absorbed 2 souls(specifically Whitebeard and Thatch, ironically those two would make him complete since Oda separated them for this show).

In some legends Cerberus was known to eat or rip out the souls from his victims. I believe that’s what Blackbeard did to both Thatch and Whitebeard.

Another possibility is that he stores their souls in the rings he carries. Let’s say he did take 2 souls that would mean he has 3! What? Yes i said 3!
Blackbeard’s newest appearance seems to confirm that. The number 3 shows itself yet again!

Teach has a lot of sets of three: three guns, three beard braids and his three skulls on his flag.
*Theory by PrincetonProduction