kGE has released a video teaser for v3.6 here. The secrets of the 5 elements will be explored in future patches. The 5 elements are wind, earth, fire, water, and heart... Captain Planet comes to Granado Espada! The 5 elements are associated with each region of the extended map. More on the map later...
Elementalist gets a new stance! The trump series, formerly known as costumes, might end up being the top elite armor.
New pet chicken! Raid at anytime (possibly only applies for Team Arena and other daily missions related to the statue)! New raid boss in Land of the Dead!
Three new characters - Catherine (left), Reckless Emilia (middle), and Valeria (right). See New Character Details v3.6.
See also 散歩道 here and here, and the forum discussion here.
Edit: Anytime Raid is possibly for daily missions only. Added link to new character details.