the answer... I could not find... no matter how hard I tried

There are many characters in Riviera, however I will only touch on the main ones that interact with dear Ledah

Ein

If Ledah is close to anyone, it'd have to Ein. Ein's Diviner is Einherjar and is of the element lightening. He has a very innocent personality and is the only wingless Grim Angel, as he sacrificed his wings for his Diviner. During this initial mission to Riviera by way of Heaven's Gate, Ein's questions and weakness in battle seems to annoy Ledah, who wants to hurry and complete the tasks given to them.

Although he lost his emotions, when Ursula takes Ein away, a look of worry crosses Ledah's face. Hector dismisses Ein's life as expendable, but Ledah had wanted to save him. Ein aiding the sprites of Riviera was forbidden and he was considered fallen to all but Ledah, who comes to Elendia to ask Ein to return with him to Asgard.

When the two meet again in Yssgadril, they must fight. Ein defeats Ledah, who is amazed at how strong the young Grim Angel has become. Despite his demand that Ein kill him, as a defeated Grim Angel is a worthless one in Ledah's eyes, Ein refuses and promises to come back for Ledah. Instead, Ledah's ends up sacrificing himself to save Ein -- he uses his body to shield Ein from an underhanded blow Malice was about to deliver after losing to Ein. Ledah's death pains Ein a great deal.

Malice

Malice is a Grim Angel as well and her Diviner is Skadi, an ice element. She is the one who kills Ledah, with a killing blow intended for Ein. She is Hector's puppet and realizes this, having sacrificed up her future for her Diviner.

She dies in the end, Hector killing her for one of the two final souls needed to activate The Retribution.

Hector

Hector is one of the eight Magi that act as the gods proxy in Asgard. He is very cold and doesn't care about the lives of the Grim Angels and certainly doesn't care about the lives of the sprites of Riviera. Hector is one of the true antagonist of the game.

It is only later that Ledah realizes Hector only wants to activate the Retribution so that he can become god. Ledah's dying request is that Ein stop Hector.

Ursula

Ursula is the guardian on Riviera. During Ledah and Ein's initial mission to Riviera, she notices the doubts Ein has about having to sacrifice the lives of the sprites. After summoning a wyrm, she takes Ein away, first to kill him but as he does not die, she comes to realize he has a pure heart. Instead she ends up asking Ein to save Riviera, so she is, in a sense, the catalyst that separated Ein and Ledah.