My only experience with the series is playing some SCV. I thought it was pretty good, but it didn't really hold my attention for every long. I'll keep my eye on this one though as I've been thinking about giving the series another chance.
I'm sad to hear that
SCV was the one you started with, because that was honestly the most botched game in the series.
SoulCalibur has almost always been a series rich with multiplayer and
singleplayer content, where there's a lengthy arcade mode and some kind of massive arena mode to unlock new weapons and characters through something like the odyssey-like Edgemaster Mode in the first game, or the dungeon-crawling Weapon Master mode from my favorite,
SC2.
SCV was going to have those things, but Namco rushed it so quickly to market in order to get multiplayer serves up and running that Project Soul Team ended up cutting 80% of the planned content from the final product. Here's hoping
SC6 doesn't suffer that fate.
Nice! I loved the first SoulCalibur on Dreamcast - played it to death. Tinkered a little with the sequel on GameCube and PS2 (Link > Kratos BTW) and it seemed pretty solid at the time. Anything I should know about the story going forward? Reboot or no I'd love to know what I've missed.
The Dreamcast entry is a classic that I adore immensely, but
SC2 on GameCube is my favorite fighting game, period.
Storywise, whatever's important will depend on which character you follow throughout the series, since their adventures rarely intersect. One of the big story-changers that occurred after
2 was that the human host for Nightmare, Siegfried, broke apart from the evil sword's influence and embarked on a quest to cleanse his soul from the atrocities he had committed as Nightmare. But his life essence had fueled the evil sword to where Nightmare's armor began to animate and kill on its own, as a living doppelganger embodying all of Siegfried's worse characteristics. The two battle continuously throughout the series, although apparently their duel climaxed in
SC5 (off-screen, of course).
Another big story element is that in
SC4, we actually meet the godlike being who crafted SoulCalibur with his own hands---the god Algol, who made the sword as a constant, defiant equal to the evil sword, Soul Edge. He's described as the most powerful character in the
Soul series, and the only person to have successfully fought him to a stalemate was the wandering swordsman Mitsurugi.
SC5 features some nonsense about Sophitia's kids and is best avoided, since it establishes so little storywise.