Is Toland dead?

Found my theory. On the first quest for Bad Juju, "Toland's Legacy," we're told that Toland, "a once-esteemed warlock," was exiled from civilization for his obsession. In the grimoire card "Crota's End," Eris Morn finds Toland after his exile and enlists him to fight Crota. Toland tells her that Crota is a shadow in their world, and that his real being exists in an alternate dimension. Being that the only way to kill Crota is to enter his dimension and kill him there. Eris Morn and her fireteam, including Toland, enter the Hellmouth. In the grimoire card for Ir Yut, chronologically the last time we've heard from Toland (I could be wrong), it is made apparent that Toland joins Eris' fireteam to find Ir Yut and hear/learn her song of death. He's curious as to how her song is death to those who hear it, but she's somehow immune. He speculates that Ir Yut crafted the song for Crota and she uses it to pin Crota to the fabric of life and death. As far as I know, there is no hard evidence relating to remaining member's of Eris' fireteam after they meet with Ir Yut, only frequent references to her being the lone survivor. She was able to survive alongside the hive using methods taught to her by Toland. In the flavor text for the warlock bond Emerald Light, Toland says "They'll believe you are one of their own. And that is the only way." Toland gained this knowledge before they ever entered the Hellmouth, and conceivably survived alongside Eris if he wasn't killed by Ir Yut's song. It could be that Toland was killed by Ir Yut, was turned into the ash and dust that the hive are made of, and then took on a new form. It could also be that Toland is still trapped in Crota's dimension and like Crota, has taken on a shadow form outside that dimension. It could be that Toland's methods for co-habituating with the hive were more radical than Eris'. Maybe the inky blackness that streams down Eris' face consumed Toland's body entirely. It's also possible that Toland succeeded in learning Ir Yut's song and so he walks the line between life and death. "We came up from the dust and burrowed into flesh for warmth and became something new." - Xur If there's any justification to my ramblings, what remains of Toland finds its way back to Earth and shows up every week at the Tower. Nobody is able to stop him from passing through at his will, and according to his grimoire card he may have a deal with the Vanguard or the Speaker. Both the grimoire card "Ghost Fragment: Hive 3" and Eris' in-game dialog refer to the speaker having something under his mask. In the grimoire card, Eris mentions to Ikora that she's become more like the speaker and Ikora stops her before she says any more. If Toland did survive alongside Eris he would probably know the true nature of the Speaker as well, and could have arranged with the Vanguard or the Speaker to be allowed at the Tower in exchange for his silence. Hey also says some strange things if you stand next to him. For example, "My movements are to a significant degree dependent on the Planetary alignment." and the more important quote "I think the cells of this body are dying and some of the cells, in this body, began on this world. How strange to return."

I wrote this lore theory awhile ago that basically Toland is Xûr. I had a it of interesting evidence and leads. I shared it with the group and everyone was pretty intrigued but it's lost in the chat now.

If toland is no longer here, it is not by the darkness's own hand. He communed with it, and learned great but terrible things. The darkness views toland as it's own. And toland could not have died to old age, or any other cause. Toland lives, perhaps on the moon, perhaps beyond even Mars, out in the dark.

Nether dead nor living. Existing on a plan of existence only few will ever see. That is his resting place without rest. This is where we reside.

Toland knows too much about the darkness to get lost, he's not dead because he's an all powerful warlock. Maybe he's not gone but abducted? Maybe the hive need him for information, he can speak to hive and probably knows more about the hive than the hive do themselves, but Toland has another purpose for giving them info. The hive must have something he wants desperately, and he still works as a double agent in order to obtain it. Maybe the location of Oryx?

Toland knows too much about the darkness to die, if he was in danger he would know before it happened

Accounts of his current status are limited only to Eris. She is the only link we have to what happened down in the Hellmouth. Which is safe to say he is dead. (Although his death was never on screen / mentioned in detail, unlike Tarlowe's.) I'd like to think he died finally understanding the liturgy of death, seeing as the lore suggest that was his main reason for joining up with the team.