Toland the Shattered is an old Guardian. He was once revered, but apparently lost his mind and was "exiled"
Some theories suggest he is now apart of Xur
Toland the Shattered was recently revealed to be part of the Firearm led by the Rogue Guardian Eris. He perished at the hands of Crota in Eris's attempt to raid the moon
Not to the hands of Crota. To the hands of Ir Yut maybe. He was trying to learn or hear the song of Ir Yut hes also possibly the one to put the chalice with all his fallen allies light in Crotas throne room.
An interesting theory. Quite possible as well