^^^
But what about the first one?
However, things take a drastic turn on the night before their journey. Riku, likely unable to leave the islands without knowing the truth, opens the door in the secret place and the Heartless, beings of darkness, invade the islands, seeking out the world's heart. Both afraid that a storm would destroy the raft, Kairi and Sora set out for the island. Sora finds Riku first. However, while Sora is concerned for his friend's safety, Riku is only obsessed with finally escaping the islands. Darkness surrounds the two, and Riku disappears into it, while Sora gains the Keyblade.
Riku eventually ends up in Hollow Bastion via the Corridor of Darkness, separated from his friends. There, he is found by Maleficent and she offered shelter and protection.
Though Riku is provided a place to stay, Maleficent begins corrupting his mind, convincing him that Sora has replaced him and Kairi with Donald Duck and Goofy. She claims that the only way to save Kairi, who has lost her heart to the darkness, is to ally himself with her and her band of villains, while abandoning Sora. Not long after, he meets Sora in Traverse Town, takes a look at his Keyblade, holds it for a few moments, and gives it back to Sora without it disappearing from his hand - a foreshadowing of Riku's role as a Keyblade wielder. After his reunion with Sora in Traverse Town, Riku begins to agree with Maleficent and officially starts his stay with her. However, he is still highly suspicious of her motives.
As the days progress, Riku becomes steadily angrier at Sora, convincing himself to hate his old friend. He obtains a blade from Maleficent called the Soul Eater and teaches himself to use it, believing it will aid him in his search for Kairi's heart.
Jealous maybe......I wouldn't say misguided.

BTW in chain of memories, he fights Maleficent be himself and kicks her ass.....so a Sora vs Riku fight would result in Sora getting his ass handed to him.