Warning: Spoilers Off applies to these pages. Proceed at your own risk.

Fire and Ice

Luffy stops believing in Jack after Sabo "dies". Jack tries to hug him, but Luffy runs right through him.
Ace and Jack try and fail to get Luffy to believe in Jack again. Jack goes with Ace on his adventure since there is nothing left for him on Dawn Island.
Jack escapes Blackbeard's shadows just in time to see Akainu impale Ace through the chest. Jack sobs as he desperately begs the Man in the Moon or Mother Nature to save Ace.
Luffy is left screaming and blank-eyed when Ace's body disappears.

Embers and Frost

Seeing Ace slowly lose hope as he realizes he is losing track of reality and no one is coming to rescue him from Pitch.
Ace pretends to be a hallucination in order to get Luffy to leave him behind. He flinches when Luffy says he is not real.
Haruta does not know that Pitch attacked Ace and believes he pushed Ace to attempt suicide. He is distraught that he treated his little brother so cruelly.
Ace's shame after the Whitebeards that do not know about Pitch believe he slashed his wrists in an attempt to kill himself. Many treat him like glass or watch him constantly while others glare at him for trying to "kill himself".
The broken trust between the Straw Hats (and Ace) and the Whitebeards after the failed Black Sand extraction attempt. The Straw Hats and Ace went behind the Whitebeard's backs and it hurt the latter— particularly Marco— deeply. Marco does not talk to Ace for several days.
Garp tearfully apologizes for not helping Ace at Marineford.

Tear Jerker / Summer and Winter