Part 1 - Sabo and Dragon
When Dragon found Sabo he was barely alive but got Kuma to use his powers to take out all the damage he took like he did to Luffy. After that all he needed was to be stitched up.
Sabo - "Why did you save me?"
Dragon - "Because Kuma is a bear and has needs."
Sabo - "What?"
Dragon - "Er I mean that you reminded me of my son."
Sabo - "What are you going to do now?"
Dragon - "I'm going to take you to my headquarters and teach you how to be a revolutionary." "Your speech inspired me and I think you would make a good member."
Sabo - "Are you sure I can do it?" "I really needed to get away from there and wanted to be a pirate"
Dragon - "Yes I am sure and I will train you along with the others."
Sabo - "Well I am ready to start now then."
Dragon - "You need to rest for now we can start training in a few weeks."
Then Sabo became a member of the revolutionaries current whereabouts unknown.
Part 2 - The Conversation
In chapter 631 we see Crocus and somebody talking. This was none other than Yorki who survived his illness but decided to live a quiet life. He assumed his crew had died because he had heard nothing about them.
Crocus - "Have you heard about the Straw Hat Pirates?"
Yorki - "From time to time. I like the sound of that crew."
Crocus - "I heard they have 9 members now. When I met them they only had 5." Strangely enough the Soul King is part of their crew if you heard about him."
Yorki - "I heard about him. "I know what you're thinking and it probably is him. He had a strange Devil Fruit power after all."
Crocus - "I assume he will come here to see Laboon when they finally reach the end of the Grand Line."
Yorki - "That would be good." Laboon would be so happy."
Crocus - "So how long will you be staying before you go back home?"
Yorki - "Just a few days" I hope I can see Brook one day too."
Part 3 - Makino's Baby
The father is none other than Ace. He had gone back in his search for Blackbeard and encountered Makino again.
Of course since they flirted before something was bound to happen. If you remember Ace was in the womb for 20 months which is 1.7 years and is pretty close to 2 years. Since Ace had been carried like that he inherited this from his mother and it carried over to Makino and the baby. The reason she survived was because what Ace got from his mother made it stronger for the baby. So Ace's will and bloodline lives on. The Marines never expected this.