Halaster Blackcloak
{{Character|
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| image=
| name=Halaster Blackcloak
| aliases=Hilather, the Mad-Mage of Undermountain, Lord of the Underhalls
| gender= Male
| race=Imaskari Human
| parents=Unknown
| dob=Unknown, between –3920 and –2488 DR
| pob=Unknown, possibly Imaskar
| occupation=Archmage, Arcanist, Custodian of Undermountain
| affiliations=Madryoch (ex), Imaskar, the Empire of Shoon, the Seven of Undermountain, Undermountain, Mystra
| siblings=Unknown
| spouse=None Known
| children=None Known, Apprentices include Arcturia, Jhesiyra Kestellharp, Muiral the Misshapen, Nester, Marambra Nyghtsteel, Rantantar, and Trobriand the Metal Mage
| class=Arch-Wizard
| alignment=Unknown
}}