Here are the event details translated by SleepyPig. Thanks both

Event One

Event Duration: Until the next patch
Event Info:
  1)Monday to Friday- Stay Online for 30 mins and 1 hours to gain x1 Halloween box and x3 Halloween box respectively
  2) Saturday to Sunday- Event Rewards Increased. Stay Online for 90 mins and 2 hours to gain x2 and x3 Halloween box respectively
  3) The box contains sweets, Halloween hat, ghost transformation potion,Halloween tail,tattoo, special halloween box and many more

*4 Different types of Halloween Hat

Additional Info From Sieg
Daily boxes and weekend boxes are DIFFERENT. A permanent tail can be gotten from the daily box, it's not a bug, which some people have been asking about. The weekend boxes supposedly has a permanent tattoo according to their super moderator. There have been players whining on their forums about not seeing it at all, so it's up to people what to believe.

Event Two

Event Duration: 10/18 - 11/17
Event Info:
  Log in Daily to receive 2 Scroll of Resurrection
  Log in everyday throughout the whole event to receive a shiny red wings 30 days. Untradable

*Event rewards to be given out 2 weeks after that

Event Three

Event Duration: 10/18-10/27
Event Info:
  PVP Elimination Mode 16 or 8 in a room. 4 pple in a room doesn't count ( Idk what is this. I seldom play PVP)
  Achieve 1 win to receive x2 Goddess tear Drop

*Only can receive once
Event rewards to be given 2 weeks after it ends

Event Four

Event Duration: After the Halloween Patch (Which is now)
Even Info:
  1)After achieving certain level and certain total character level, you are able to use the integrated skill
  2) From 10/11-10/24 Midnight，You are able to use the server character transfer.

Character Transfer URL：http://act.dn.sdo.com/jsfl/index.asp

Event Five

Event Duration: Ends on 11/2 00:00hrs
Event Info:
  1) Obtain the 3 parts Halloween items (万圣节精灵、万圣节翅膀和万圣节纹身) for a character, You will get x4 lv 60 Heraldry Bag and x5女神的气息( The new dailies for lvl 60.)
  2)Obtain the 3 halloween item set( Halloween costume, Halloween Mount and  Pumpkin Cat's pet), you will recieve 恐怖亲王之礼 - 龙之谷限量周边大礼包( Dragon Nest Limited Edition Big Gift)

Additional Info From Sieg
Till 2 Nov Midnight, those who have the Halloween item set - , the tail and the tattoo will get 4x Level 60 crests + 5x Goddess Breath (Not sure if that's the name of the item in game)

Till the same timing as above, those who have the COMPLETE Halloween set, which includes the above items + costume + mount + pet, will get 恐怖亲王之礼 which is a Dragon Nest Limited Edition Big Gift Pack, which includes (I have no idea what items they are, sorry, but translates to Crazy Duck, Haunting Spirit, and 10 players out of these lucky/rich souls will have a chance to obtain )

  3)Halloween Pet buy from tuangou: http://tuangou.sdo.com/Index.asp?from=89

Event Six

Event Duration: 10/24 00:00hrs

Event Info:
Procced to the east side of Saint Haven"道具合成NPC" to combine rings
You will receive C Grade 【灿烂的星之碎片戒指】（Magic and Physical attack +2%，体力+15）

Thanks Sieg for the additional info!