Thanks for the tag Rayan! As of right now, I can't exactly understand why people are saying that Drake's showing is disappointing thus far when nearly 400 chapters passed from his first appearance before we saw his Hybrid Form and nearly 500 chapters passed from then before we knew he had any named attacks (which only just happened 6 chapters ago when he finally switched sides). In the case of Haki, roughly 225+ chapters later, Oda reveals--via a COVERY STORY--that Drake has Busoshoku Haki.
If anything, we are still waiting to see what other tricks Drake actually has up his sleeve, so it's interesting to speculate about that since Oda still hasn't totally revealed Drake's hand. The Wano Arc seems to have been brought up as Drake's major appearance arc, and I fully believe that now that Wano has come into the spotlight AND Drake has switched sides, we're going to see more of his abilities.
As for OP: Pirate Warriors 4, if we see any of those moves confirmed in canon, I think that'd be pretty cool IMO especially the-flying- slashes-from-a-tail-whip which we've never seen a Zoan actually be capable of doing; however, we have seen that Drake is capable of claw slashes both in-game as well as in-canon so it's possible some in-game attacks/moves are canon--which ones, remains to be seen.
EDIT:
Now when it comes to what Drake has in store, I don't it would be too much for him to have at least Kenbunshoku in addition to Busoshoku as well as any of the Six Powers and more Sword/Mace techniques. I also feel like Drake should have something that stands out as a Zoan (aside from just being an Ancient Zoan and apparently the only one in the Marines at this point in time), but I'm not exactly certain if Oda will go THAT FAR.
The idea of an additional form is appealing, but we have noticed that Drake has a tail which was added in Chapter 996 during his fight with Apoo (and we also saw his clawed feet to a degree as well). As for why Drake didn't have a tail in his initial hybrid appearance, I really have no idea.