History:  Nestor's history, if he's not simply a figment of Quicksilver's imagination, is unrevealed.  He has dropped hints that he knows Quicksilver better than he knows himself, and claims he knows what Quicksilver's true potential is unencumbered by responsibilities to his family or the Knights of Wundagore.  IF the hints are anything to go by, then he may well be from an alternate future somewhere, though what kind of future (i.e. a "mutants rule" one, a "mutants hunted" one, etc.) is unrevealed.  Based on what little we see of his face, he could be a blood relative of Quicksilver and Magneto's, but again, that is unrevealed.

(Quicksilver#8) - In the Knights of Wundagore's New York state base the Haven, Quicksilver (Pietro Maximoff) was recording his thoughts and feelings on recent events in his life (specifically Crystal's leaving with their daughter Luna to sort her feelings out after a stay on Heroes Reborn Counter-Earth) when he was interrupted by a mysterious robed figure who told him to let everyone in his life go -- family, Knights, Avengers, everyone -- because they were weighing him down and keeping him from achieving his full destiny.  Pietro began arguing with the figure, but was interrupted by Sir Ram.  Pietro chastised Ram about interrupting his conversation, but when Ram asked who Pietro was talking to; Pietro noticed the figure had vanished without a trace.

(Quicksilver#12) - Held prisoner in a dungeon at the High Evolutionary's Citadel of Science (held by Exodus and the Acolytes (followers of Magneto), who had earlier chased the HE and his Knights out of it for their own purposes), Quicksilver was reviewing the events of the last few issues when the mysterious figure knocked out his guards and once more approached him, and chided him for indulging in self-pity when so much was at stake.  He told Quicksilver to remember who he was, and who his father was (a.k.a. Magneto), and that his strength and power flowed through Quicksilver as well.  And told Quicksilver that to break his chains all he had to do was concentrate and visualize the manacles breaking away from his body, and his powers would do the rest.  After Quicksilver was free, the figure told him to always to remember who he was and who his father was, since that would be the only way for him to win the coming war.  When Quicksilver demanded an end to the games, the figure told him he'd tell all eventually, but that he didn't have the strength to remain here now, and vanished without a trace once again.

(Quicksilver#13) - In the aftermath of the Battle for Wundagore, after Quicksilver left the leadership positions of both the Acolytes and the Knights, the figure once more approached and chided Quicsilver on standing around feeling sorry for himself after winning the battle.  The stranger told Quicksiver his name could be Nestor, but that would tell him nothing of who he really was, and goaded Quicksilver into a trip down memory lane.  While Quicksilver told him his origin and life up to that point in his history, they visited various places that were important to Quicksilver's history, such as Bova's hut on Wundagore, and Magneto's old castle base, with Quicksilver running the distance between each place, and Nestor somehow arriving in each location long before Quicksilver did.  At each point Nestor kept hammering on how Quicksilver defined himself (or rather, how he allowed others to define him) and on who he really was deep down.  When Nestor pushed him on how he endangered his daughter's life by wanting to expose her to the Inhuman's mutagenic Terrigen Mists when he realized she was born a normal human, Quicksilver punched him and declared he'd no longer listen to Nestor, and ran.  Eventually, at the Knight's New York base, Nestor found Quicksilver gathering the recordings he'd made for his wife Crystal while he believed her dead, and stole them out of his hands before Quicksilver could react, claiming that giving those recordings to Crystal would forever hold him back from his true destiny.  Easily evading an attacking Quicksilver, Nestor went down to Lord Delphis's lab, where he told Quicksilver once more that giving Crystal the discs would be his undoing, but Quicksilver managed to knock Nestor into a power cell and grabbed the discs before they could be destroyed by the cell.  While Quicksilver raced to escape the Haven and give the discs to Crystal, Nestor reflected on how the encounter was done, and how it had to be done that way, before the base exploded.  Later, after Quicksilver delivered the discs and started out on his own quest to learn his true self, Nestor watched from a nearby building, apparently to make sure Quicksilver was headed in the right direction.

Comments: Created by John Ostrander & Joe Edkin (writers), Derec Aucoin (pencilers) and Rich Faber (inkers).

Quicksilver#12 was part four of the five-part Siege of Wundagore storyline that crossed over with the Heroes for Hire title that summer.

I'm not sure where Ostrander and Edkin were intending to go with Nestor, or what his connection to Quicksilver really was.  They seemed to have an idea they were following, but the book's cancellation nixed those plans before they could bear fruit.  Four theories on who/what Nestor was:

1. He was a figment of Quicksilver's imagination all along (unlikely, since he appeared in a few panels by himself after Quicksilver had left him)
2. Nestor was a future Magneto, or the present one in disguise (unlikely, since surely Quicksilver would have ID'd him right off, or right after he got a good look at Nestor's face in #13)
3. Nestor was Quicksilver himself, who had somehow figured out how to use his powers to travel backwards in time, and goaded his past self into making decisions that he needed to make for his own, and the future's, good (interesting twist, if this was what Ostrander and Edkin were going for.  And by the way, this would be from using Quicksilver's original power set, not the ones he got post M-Day via the Terrigen Mists)
4. Nestor was a future blood relative of some sort of Quicksilver's (i.e. son, grandson, nephew, cousin, etc.) and wished to alter history (or make sure history went down as recorded) via goading Quicksilver into making certain decisions for himself (most likely of the four, I think).  Until someone chooses to pick this plot up again, it will remain a mystery, unfortunately.