Blackbeard is actually a therapist. His issue? He only plays on extreme difficulty, which is why taking the worst degenerates from Impel Down Level 6 wasn’t enough. He needed to further enhance their issues, which is why he got them specific devil fruits:
- Blackbeard himself loves to shake the world and shock people so he got a devil fruit that would allow him to view the shocked expression of every devil fruit user he encounters by turning off their powers and also a devil fruit that lets him literally shock and shake everything.
- Shiryu is a backstabbing menace, so Blackbeard encouraged this behaviour by giving him a devil fruit that allows him to be an even bigger stealthy asshole that also allowed for more underhanded tricks (e.g. invisible traps, turning the tip of his sword invicible to deceive others regarding their range).
- Burgess is a pretentious asshole that loves challenging people, but is a sore loser. To improve his complex, Blackberad gave him a devil fruit that makes him even stronger.
- Van Augur pretends to be calm and analytical, but we know he’s an evil asshole since we saw his grin after the failed kill shot on Ace. He’s also a sniper. Combining all that makes him the typical egoshooter player who alternates between 360 No Scope and camping. His devil fruit is perfect for both styles.
- DocQ was born “chronically very ill” according to himself. He’s called the “Death God.” Irrespective of whether he’s actually sick or has Munchhausen Syndrome, Blackbeard further improved his sadist nature by allowing him to inflict all kinds of illnesses on others (and potentially himself) to project his hatred of his own condition.
- Stronger pretty much fits DocQ’s theme. Sick horse that can now fly! Could also go with ugly horse that thinks he’s Cavendish’s Farul or bland horse thinking it’s a mythical being, so Blackbeard allowed him to turn into a magic flying horse!
- Laffite already has his devil fruit. The corrupt sheriff with angel wings is poetic – what’s your guess regarding his devil fruit? Zoan Dove, Owl or Siren? I kinda like the idea of a feather paramecia (think Hawks from BNHA).
- Sanjuan Wolf also already had his devil fruit, so I’ll just drop some info: he is the largest giant who has ever lived thanks to his devil fruit, earning him the epiphet “Colossal Battleship.” He was also 99 years old after the timeskip and his birthday is March 2nd. Since Tama recently had her birthday on March 3rd, Sanjuan Wolf is now 100 years old. I hope Blackbeard baked him a small cake which Wolf then inflated as much as he could.
- Vasco ‘rapey vibes’ Shot is known as the “Heavy Drinker”, so Blackbeard obviously got the alcoholic a devil fruit that lets him manipulate alcohol. Was probably cheaper than the lifelong sake subcription.
- Avalo Pizarro, the “Corrupt King” who was toppled by his own subjects now has the ability to merge with the whole island, meaning he gets to perfectly control and manipulate “his” kingdom. Giving powerhungry corrupt rulers more tools to subdue their subjects never ends bad.
- Catarina ‘I peel pretty women’s faces off to wear them’ Devon, jk, she just collects their heads, probably due to an inferioty complex. Blackbeard’s gift allows her to transform herself into others, so that she really gets to feel how much prettier and just overall better than her other people are.