The main difference between the two guilds is that the Silver Knights mainly rely on hand-to-hand combat, while the Grand Chase uses a combination of melee, archery, and magic.
Jin is the first Silver Knight seen. In the events of Ruins of the Silver Knights, he was trying to flee a Black Fairy Queen. Upon seeing the Chase, he fights off a Undead Fighter, but then the Fairy appears. Jin and the Chase then scare her off afterward, using his powerful chi. When the Chase introduces themselves, Jin exclaims that the Silver Knights were identical to that guild. He joins them in hopes to rebuild the lost nation and restore it's glory.
Amy is the second Silver Knight to be introduced. She is first seen at Lake Aurora, but does not interact with the Chase whatsoever. She is then seen again the Temple of Cuatal attempting to flee, stopping to bless the Chase with her Dance Fever. Amy then appears again after Samsara's defeat. She the joins the Chase to help them fight off the Ascendant God.
Asin Tairin is the guild's second-in-command and Jin's mentor. Sometime after Victor's betrayal, hordes of monsters began to approach what's left of the Silver Knights. Under Tairin's command, he ordered Jin to flee in order to save himself. Tairin thought that Jin did not survive the onslaught. He survived the attack, but badly wounded. He was then found in the forest by a young boy who healed his wounds and decided to repay his kindness by teaching him the ways of the Silver Knights. He eventually died saving his new student from another horde of monsters.
Victor was the leader of the Silver Knights and who betrayed his own organization, starting a new one called the Black Knights. He slaughtered every single Silver Knight as he deemed them "weak", joining forces with the Ascendant God so he can "protect" Silver Land (while ironically stripping its water supply and polluting several areas with poison). In his own Fortress, he is seen by Jin who then vows to avenge his lost brothers. The Grand Chase believed in his power, and doing so, he killed his ex-leader. Victor then asks for more "strength" from the Ascendant God, but he tells Victor that he outlived his usefulness and didn't need him anymore. Victor dies shortly afterwards.
King Guang is a giant sea serpent that was originally known to guard over Silver Land's waters. When he was seen in his Fen, he is half possessed. Ultimately, Guang gives in and attacks the Chase against his will. The Chase fight back, defeating him. He thanks them and informs them he was corrupted. Before the Chase can heal him, he requests to let him die, so that the water he stole will go back to wherever he took it from. Jin, sorrowed by the loss, promises to avenge him.
King Fang is a giant worm that is King Guang's beloved friend. He was brought false information by a messenger, and became outraged. The message stated that King Guang was "assassinated". The Chase fight him off and defeat him. Fang apologizes to Guang as he failed to avenge him. Jin pulls the point saying Guang "sacrificed" himself, not he "died". Fang apologizes to the Chase, as he acted so rashly. The Chase promise to avenge both Guang and Fang (though Fang didn't actually die) by hunting the source of Silver Land's corruption. Before the Chase set off, King Fang reveals that Victor is responsible for Silver Land's corruption.