Shiki Might Appear and Join Cross Guild - One Piece

Theory about the future of Cross Guild (apologies for grammatical errors)

Shiki is going to join the Cross Guild because they have similar objectives: both are searching for ancient weapons and hate the world goverment. He failed to recruit Roger and later Whitebeard but now that there is “Cross Guild“ a strong pirate group that is threatening the world goverment, his chances of success are great. Maybe the time has come for Shiki to make his move. Shiki’s name also fits perfectly into the group, Sir “Crocodile“, “Hawk“ Eye and Golden “Lion“ Shiki, all of them have epithets of apex predators.

The ancient weapon he was looking for when he was talking with Roger was probably Uranus because Shirahoshi wasn’t born and Roger didn’t meet Oden at that time. I don’t think that the egg that was on Roger’s ship is Uranus because why would he ask Roger for the location of the ancient weapon when it’s right infront of him? I think that this egg belongs to Merveille, the island Shiki visited in chapter 0 and that he is trying to tame the animals there with help of Dr.Indigo.

Theory about “a certain pirate“:

The crew member of Roger probably know the location of the ancient weapon and since all of them disappeared and Buggy laying low in the east blue, there was only Shanks left for Shiki to ask. He probably visited him or sent someone to ask him where the ancient weapon is and to join him but Shanks, of course refused to do so. Sensing the eminent threat Shanks went to the Gorosei to talk about Shiki.

Theory about Blackbeard (this is going to be stretch):

There is Imu carrying 2 wanted posters, one is Luffy and the other one is most likely Blackbeards poster. Imu is comparing Luffy’s Strawhat with the big frozen Strawhat but why is she or he carrying Blackbeards wanted poster? I can’t see something special on his wanted poster but who knows, maybe somewhere in one of these rooms, there is a frozen body that looks similar to Blackbeard.

In this panel there is Shirahoshi one of the ancient weapons and Blackbeard but why? I don’t think that he is an ancient weapon but maybe he was able to locate Uranus. Shanks met Blackbeard for some reason in the past. I wouldn’t surprised if he told the Gorosei.

Let’s assume Shiki joins the Cross Guild and Blackbeard knows the location of Uranus. Im sure Shiki would try to recruit Blackbeard or at least try to form an alliance with him. I can imagine a scenario in which they wouldn't get along and dispute over who should be the leader. And while they’re arguing, some agitated marine spy mistakenly sends the wrong message to the marine HQ in which he declares Buggy as the leader. Buggy failing up again, i wouldn’t be surprised if his df awakens once he gets killed, like Luffy.