I moved this to the Dark Souls II version of the archives where you'll find more expertise on Vendrick and DSII to hopefully stimulate more conversation.
I think there's a chance he is A chosen undead, but likely not the one from Dark Souls. The reason I think that is because it then invalidates a large segment of chosen undeads that we all played. You could say he's just one version since the games rely heavily on an infinite universes concept. However, it's just cleaner to say that we all made our own chosen undead last time, some other stuff happened, then Vendrick became part of the current cycle. There's also a (possible) radical shift in geography. I'll spoiler some stuff below about that, but going on mostly faith that Lordran turns into Drangleic, there's a lot of differences in geography. All of this transitions nicely into your next question.
There's some subtle things like the Vendrick idea above that might reasonably be perceived as evidence that it's more than one cycle. But since we don't know if Vendrick is from DSI, we can't do anything further than make guesses.
There are less subtle clues, but again nothing conclusive. Straid makes a direct statement that many kingdoms have risen and fallen. I might be imagining things, but I believe he even goes so far as to indicate that these kingdoms have been "in this spot" or some other variant alluding to "same geographical space." Shalquior is a little more vague but she also references the cycles and insinuates lots and lots of time has passed. Now some things would need to be taken on faith. For instance, if DSI is the literal beginning of the cycling (lords find souls) then Shalquoir's words combined with Straid's dialogue would CONFIRM that there have been many cycles between the two games. Shalquoir indicates that the "Old ones" are now so ancient that their names can't even be remembered. Except she essentially names at least one correctly. The interpretation for me is that their current names are obviously known and Shalquoir is alluding to their true beings' names being forgotten (the original holders of the four souls). So, if Gwyn and company were the ORIGINAL owners of the souls, then time has made everyone forget their names. It would also mean the cycles began with the first game, so Straid's assertion that many kingdoms have come and gone would mean that this is not the second cycle most likely.
However, as I noted in your other thread, I don't fully buy into Gwyn and company actually being the "first" cycle. As I've noted in another thread or two, DSI and DSII don't share the same pantheon (or anything resembling similar pantheons) or creation stories. I could delve deeper, but essentially, Gwyn and the Lords are the pantheon and the world as we know it was created when they found their souls. In DSII, the four Old Ones are NOT the pantheon or even part of it. The "gods" of this world are referenced but not seen. The Hunter's bow even directly states that one goddess was never divine, but legends and retelling of her story made it so she was worshipped as one. My take is that the game is telling us that gods in this land (whatever cycle) are merely "who has enough power to be worshipped." The creation story in DSII is pretty much nonexistent.
What this means for our purposes is that the creation story of the first game has a high potential to be exaggerated or even completely incorrect.
My belief is the answer is in the middle. The finding of the Lord Souls marked the beginning of that cycle and that's what was then translated into the creation story. Meaning that we're actually left wondering if DSI is the first cycle. In short, we can provide guesses in either direction, but the game never explicitly tells us the answer to any of these questions. While I believe there's some cycles between the two games and can write long posts elaborating my point, I can't prove it.
The geography is important to your question, but it's almost impossible to say for sure, just like the rest of this.
I won't go into all my evidence, but my money is strongly tied into the idea that Lordran turned into Drangleic. I'll call them the same "land" in my discussion and everything from this point is under the assumption they're the same land.
-Option 1: They're geographically in the exact same location-
Lordran fell and Dranlgleic was built on top of it. In this event it's highly likely that there were many cycles in between the two games. While there are some similar things that creep up, no one would say that the two regions are the same. Dark Souls took place under the shadow of the mountain Anor Londo is built on and appears to take place pretty much at or around the mountain. DSII features a broader range of geography and common elements are not the same. If you think Anor Londo became the very similar Heide's location, imagine the geography changes needed to flood a mountain. And then ask yourself how the buildings remained up. The end idea is that they're probably not the same spot, but maybe one was built to look like the other. Howeer, if you traverse the abyss in DSII you'll note architectural elements similar to New Londo. In this event, maybe they ARE the same place, but the geography is unrecognizable. The same goes for the Altar of Sunlight in Harvest Valley. Elements appear to have been retained, but the surroundings are different. It takes a lot of time for that radical of a change, therefore the evidence in this case is that there are numerous cycles in between.
-Option 2: They're in the same land, but not EXACTLY-
There's a couple things that could be the case here. Lordran seems to be all one fairly small geographical region. The Maps provided to us for DSII (collector's edition one and Majula both match) show a lot of area we "travel" but don't actually get to see. In other words, DSII is meant to take place over a wide swathe of land. If DSI is a smaller region, it's possible we only visit the pertinent locations in the first game, and the second game is just a larger geography. In that event, Lordran elements might be found in Drangleic but the meaning behind it could be suspect. For instance, the Sunlight Altar in Harvest Valley. Is that where Undead Burg was, or was the Altar moved? It's pretty far away from Dark Chasm entrances yet the Burg was close to New Londo. Meaningful, or does it make a difference since we enter portals to reach the Chasm? The Lordvessel might be in the basement in the Majula Mansion. Same thing, does the distance to other potentially known objects matter? We can't tell anything more than "some elements survived the cycles."
I wrote two very lengthy articles (links added at bottom) about something I feel strongly about that I call "spatial distortion." We know time is distorted in both games. In DSII, they go out of their way to show us how far away each location is from the next, yet give us a completely different experience. I won't delve into it here as I've written enough on the topic. However, if this applies to Drangleic, it might also apply to Lordran. I think it does, and have some evidence of that as well, but I digress. In that event, the literal locations of things are then less determinate, meaning that it'd be ultimately impossible to tell what geography in Lordran became what geography in Drangleic.
In Drangleic, we can say for sure based on maps that we explore a tiny fragment of the known land. If the same were true of Lordran we'd need a map of known locations in relation to the entirety of the land to make a judgment. We have a map in the first game, but it shows us the world as we experience it. It may or may not the world as it actually is. Dark Souls II gives us a map that's the opposite. In short, we can't compare the two maps and make any logical conclusion so therefore we have no way of translating the geography and no way of making a guess on how long has passed between games.
It's even possible based on everything I've just said that DSII comes BEFORE the first gamehttp://fextralife.com/iron-keep-a-castle-in-the-clouds/http://fextralife.com/iron-keep-a-castl ... ight-spot/