"Ha! I lured you here like lambs to the slaughter. Your souls shall fuel my power, making me a proper servant for Lord Malthael!"
- Pontius(src)

Pontius, The Conjurer, is a Unique Dark Summoner found in the Westmarch Commons in Act V of Diablo III. He spawns for an unmarked event: as the Nephalem approarch, he kills a dozen of citizens and absorbs their souls.
In combat, he has Molten, Mortar and Reflects Damage affixes, and is assisted by multiple Reapers. He can also summon up to 2 Hellions at a time.
Upon death, he has a chance (or at least had such in beta) to transform into Pontius, Scourge of Malthael, a unique Punisher, with same affixes. The exact chance to transform is unknown: possibly depends on whether or not the Exorcists were killed before or after Pontius himself, or just if he manages to live long enough in battle.
Trivia
- As Pontius can summon Hellions, it is likely he is a former member of the Coven.