which manga chapters...

which manga chapters have blackbeard, whitebeard, and dragon or anyone else other than the ice marine dude thats powerful enough of a character in one piece to obliterate luffy? Ive been reading some forums about dragon and all these guys that luffy has to overcome for pirate king but i dont remember reading/seeing em from reading the manga. just wanna know so i can go back and read about em

Well Dragon appears at the end of chapter 100
Whitebeard appears in chapter 234
Ace's first appearance is in chapter 154