SPOILER:

- Save you from angry street gang
- Save you from adoptive brother's lie and attack
- Weird shit start to happend and he still with you
- Weird shit start to become bizarre and he is still with you
- Resourceful enough for help your italian bro
- Resourceful enough to survive bizarre shits
- Travel to America to help your widow and an orphan
- Find oil and share profit
- Form the Speedwagon Foundation
- Never move on your widow
- Raise your kid
- Raise your grandson
- Survive crazy vampire Hamon master attack
- His Foundation make portable UV laser beams
- Has a personal army (could be ex-ogre street gang) wich save your grandson's live
- Could be that he allowed ex-nazi scientists to make a fresh start after the war
- Wich mean his Foundation make cyborg limbs too
- His Foundation give money,vehicles, manpower and technology to your grandson
- FOR FREE
- Even after he died

And i didn't even read the manga to know other details!