Hello, first off welcome back to Vindictus. As for your question about the event items and how to gear. Try to go for a budget build: +15 astera weapon, +15 dullahan armor set, +20 Frozen Will and Frozen Desire, +15 devil's crystal, +15 barrier belt, a pair of copper bracelets with the sapphire and emerald slot on them, a Sage's Chaos Book of Succession, and a mysterious cat statue. I hope that helps, if you need more help, just message me either on forums, in-game, discord or whatever.
I've failed a fast es @ 100% success rate before (N G L). I really wish I had recorded that enchantment because it was troll to the max, but I just didn't expect it.
I've also failed a milletian weapon:
8x from +12 to +13 (had to complete the failstack)
9x from +13 to +14 (1 away from the max)
2x so far from +14 to +15 (I won't stop til it hits +15, I'm persistent). I have invested about 1bil worth of mats into my milletian weapon, had it since June I believe and it's still in the process of being completed. Nearly half a year of consistent farming and didn't even have a chance to upgrade my accessories, all my dope went into that weapon. This is all true btw, the RNG in vindi can be very cruel.