Geez you are probably right about the future child parallel power-ups. Colon was just set up to do this…
All CoC Users Signature Attacks are Inheritable,
Roger's "Divine Departure" was Copied by Shanks
Luffy's "Pistol" was Copied by Bonney
Chinjao's "Dragon Drill" was Copied by Sai
Kaidou's "Thunder Bagua" was Copied by Yamato + His "Blast Breath" was Copied by Momo
Garp's "Galaxy Impact" was Copied by Koby
Ace's "Hiken" was Copied by Sabo
Oden's "Tougen Totsuka" was Copied by Kin'emon (And other Scabbards)
WB's Gura Signature Attack was Copied by Blackbeard + His Weapon Signature Attack willl be Copied by Weevil
Big Mom's DF Signature Attack (Misery) will probably be Copied by Pudding + Someone from Elbaph (Most likely) will copy her Ikoku
This leaves us with Doflamingo, Hancock, Katakuri, Kid, Sengoku, Rayleigh & Zoro, (+ Mihawk/Dragon/Loki if you agree They are CoC Users)
It's pretty obvious that only one who has Size, Strength & Faith to Copy Sengoku's Signature Attack is The Buddhist Urouge,
Doflamingo's Signature Attack "God Thread" is probably Copied from Imu,
Sabo's Dragon Breath is probably Copied from Dragon's Non-DF Signature Attack,
Katakuri has a Large Family, Oda can pick any of them to be his Successor,
Hancock Signature Attack is Multi-Arrows (Slave Arrow) so her Kuja Successor will try to Mimic her, probably Marguerite,
Loki is already set up with that "Mosa" Guy, so maybe that's who will Copy him,
So only ones remaining are Zoro, Rayleigh, Mihawk, Kid & Dragon ... etc
We need to find Characters who either look up to these guys or They themselves took inspiration from,