When Tom risked his prized Maxxor card in the "Castle Bodhran or Bust" two-parter in order to save a kid named Reggie, somebody he barely knows.
Bruiser, the kid who beat Tom hands over his Castle Bodhran scan once he learns what the stakes really are.
Bruiser: Castle Bodhran, compliments of the Bruiser. I used to be a nice guy too.
Also Tom's reaction to meeting Maxxor for the first time, who it quickly became very bitter-sweet for Tom after he found out Maxxor was a bit of a hot-headed jerk. At least for part one anyway.
When Maxxor healed Kaz in "Castle Bodhran or Bust Part Two".
Maxxor: Tom, you and Kaz have more than proven yourselves. Now I'll return the favor.
After Kaz accidentally gets Blugon caught in an energy field during a scanquest in "Out In The Cold". He tries to deliver the mugic Bulgon was going to give to his friend Raimusa in Blugon's place. After a long trek he finally arrives at Raimusa's place just as Pyrithion's attacking. He gets the mugic to Ramiusa, who uses it to defeat Pyrithion. After the battle Raimusa considers Kaz a friend.
Ramiusa: What is your name?
Kaz: You can call me Kaz.
Ramiusa: I will also call you, friend.
Siado once tried Taking the Bullet for Prince Mudeenu, he lived of course. Still it was nice to see the normaly stuck up Mudeenu care about one of his men.
Siado: Just doing my duty.. Sire...
After Maxxor had his courage restored to him he got into a Group Hug with Intress and Najarin.
The fact that his immediate reaction when Chaor takes a cheap shot at Tom is to block it. It's in that moment, and when Maxxor saves Tom from that cave in, which is also heartwarming, that you realize that Maxxor really has accepted Tom as an ally, and is just as protective of him as he would be for any other Overworlder.
Peyton and H'earring in "The Codemaster Chronicles Pt 1", I liked it when Peyton went out of his way to save H'earring in the Lava Pound.
When H'earring tried telling Tom to save himself. It's nice to see that he actually care's about Kaz and his friends.
The gang met and made friends with Iparu in the episode "The Ultimate Scan". Iparu is a pretty heatwarming guy.
When Peyton tore up his map of Iparu's home.
A good portion of "Dangers of Diplomacy" was pretty heartwarming when you think about it. It's the first time we really see Maxxor relax, not having to worry about his or his tribe's safety for once. He even tells Tom and Kaz a story from his childhood, which is a stark contrast to how he treated them before.
The story Maxxor tells Tom and Kaz about how he and Raznus first became real friends was pretty heartwarming in itself.
Sort of a case of fridge heartwarming, but when Chaor was attacking the Arsenal, Tangath-Toborn tosses up his signature battlegear, the Sword of Khy'at, to Maxxor to fight against Nalfarr. You find out later that the Sword of Khy'at is essentially Tangath-Toborn's lifeline, if it was somehow destroyed than he would have become a spirit and have been forced to leave Perim forever. And he didn't hesitate for a second to give it to Maxxor to help. Like brothers indeed.
Conner telling Peyton how to find a conjurer in "War Beasts", after working with Klay and Krystella to scam him. Proves that unlike the other two, he isn't a total douchebag.
Fivarth revealing his identity as a conjurer to Peyton and Kaz once he's told them of the conjurer's origins.
Peyton: (thoughtfully) So the Mipedians owe the conjurers, everything.
Peyton giving Sarah a Bear Hug and calling her "Sarbear" (his nickname for her) in "Warriors of Eternity" upon finding her alive and well after days of searching for her.
Tom finally stepping up and telling the school shrink that Perim is a real place in "Earth to Kaz" in order to prevent Kaz from being labled crazy.
A rather nice blink-annd-you'll miss moment happend in "Underworld Overthrown". After Takinom and Rarran are given the signal to retreat (so Chaor can fire the Annihilizer) Rarran hesitates and asks about the still mind-controlled Underworlds still in harms way. Takinom tells him they can't save them, and she orders him to retreat. Instead, Rarran flies back and throws some kind of attack, then quickly catches up with her. After Chaor fires the Annihilizer, it turns out the mind-controlled Underworlds survived thanks to Rarran hitting them all with a "Flame Repel Attack" just before the blast hit. Just goes to show the Underworlds aren't all Chaotic Evil after all. Turns out to be a tearjerker when it's quickly discoverd he got hit by a M’arrillian Mind Control attack and is now there puppet.
During his match with Code Master Hotekk in "Hotekk's Challenge", Tom reveals that Dardemus, while a scary looking Underworlder, is actually a Bruiser with a Soft Center who's became friends with Owis during the war with the M'arrillians, and Dardemus was now teaching Owis to do fire attacks.
Tom also revealed that Vidav had for some time been using Mugic to help restore Hoton to health.
It's small, but the scene in "Elementary" when Peyton humbly asks for a scan of the elemental of wind. After briefly consolting Enre-Hep she grants his request in a very pleasent manner (way diffirent from their first encounter).
Silv: Do as you wish friend.
The end of Stelgar Strikes, Stelgar is a creation of Mommark and is a tiny starfish like creature who becomes bigger and much more dangerous when exposed to sunlight. At the end it is driven off and is shown to have shrunk back into its original size and is sucked into a whirlpool believed destroyed but is seen drifting through The Underworld, it opens its eyes and is spotted by Rothar a Large Minotaur like creature who upon seeing him helps him up out of The Water