1. Not really interesting tbh since no emphasis has been placed upon it unlike for BB. BB is a member of the D. Clan that have been highlighted from chapter 1, with his similarities to Xebec getting more and more evident as the manga progresses. Even Kaido's origins are more of a mystery since he's apparently a 'thing' and is non human.
2/3. Like I've said that's the only interesting thing about him. To see if Shanks flips good or bad. Making him flip bad would make him 10x more interesting than this generic hero like figure to luffy, that he currently is.
But by saying BB is less interesting being he's inheritently 'evil' is wrong. That makes every other character in the series boring.
D. Clan has a will attributed to destiny. The world itself will be caused upon via a strom by them. BB is a part of this. Shanks will never be.
Shanks has barely any screen time which also contributes to him being boring. Ending the war was cool, looking at posters was cool but nothing really strikes out as interesting, ince you just see just see his power in marineford and pleasant reaction to Luffy. Again this is a very generic good guy trait. You love to see Shanks on screen (as do I) but it's hardly anything interesting.
Goresei meeting is the only thing that is interesting, which agian is to see if he flips good or bad.
Black beard has achieved all his goals and plans so far. His opportunistic nature and his ways of getting where he is, is what makes him interesting.
Also He's
- The only known person in the world to have 2 devil fruits via an anomalous 'body'. Check
- Is very active in the world of one piece and isn't stagment unlike his other yonko peers. Check.
- Is part of the D. Clan and parallels Xebec and is the reverse of Luffy. Check.
- Does not have a boring personality unlike Shanks. Check. ( This is unfortunate on Shanks part since he's a good guy hero atm)
- His opportunistic nature keeps you guessing his next move. Check.
- Has way more panel time and is more important to the story. Check.