Chaos Emeralds
From Wikipedia:
"The Chaos Emeralds are seven emeralds, (six in the original, eight in Sonic The Fighters, and seven in every other game) with mystical powers, and a recurring feature of Sonic games. According to official sources, the emeralds can turn thoughts into power, give energy to all living things, and be used to create nuclear or laser based weaponry."
Since the Sonichu comics take place in the Sonic universe (as well as the Pokemon universe, somehow), these objects from the Sonic continuity exist within the Sonichu continuity as well. Whether this constitutes ripping off Sonic is debatable; however, most people agree that Sonic borrowed the idea from Dragon Ball Z, which in turn took the idea from Journey to the West. Of course, nobody owns the rights to the intellectual property in ancient mythology, so DBZ is innocent there.
Maybe Chris isn't a plagiarist after all, just carrying on a venerable literary tradition.
Chaos Emeralds in General
Chaos Emeralds are the mystical gems used in virtually every Sonic the Hedgehog game. In the original game and its Game Gear entries, there were six emeralds. Sonic the Hedgehog 2 for the SEGA Genesis upped the number to seven, where it remains to this day. The only exception was Sonic the Fighters, where there was eight for who the hell knows what reason.
What these MacGuffins can do exactly is unknown, but for the most part, they transform characters into their super forms (Sonic -> Super Sonic, Shadow -> Super Shadow, Silver -> Super Silver, Knuckles - Hyper Knuckles, Chaos -> Perfect Chaos) through positive or negative emotions. In Sonic 2006, they've been shown to resurrect the dead. Beyond that, nothing else is known.
Chaos Emeralds in Sonichu
The Chaos Emeralds are first shown in Episode One (Sonichu 0) circling Sonic. He uses them to turn into Super Sonic and battle Perfect Chaos. When Super Sonic slams into Pikachu, the collision transforms Pikachu into Sonichu and releases the Chaos Rainbow, unleashing the Chaotic Combo eggs back through time and turning a Raichu into Rosechu.
When Chris is sucked into the Time Void, the Chaos Emeralds are suggested as replacements for the Sonichu Balls, but this is never mentioned again (not unlike most everything else Chris tosses in).