The event runs until March 31. If you want to take part, open up the special interface by hitting the 9 key. The official event site provides a bit of lore background on the event,
“A new page in its history has already began. Mysterious Terra, the homeland of the Mechanoids, has welcomed our pioneers with its inhospitable landscapes. Many theories have been confirmed: William Wynd, Terra's leading scientist, gained immortality and later became known as the Integrator.”
Rewards for the event include Titan Form Symbol which increases your max health and protection against control by 40% for 20 seconds. These bonuses are halved when in divine form.
Other rewards include Gust of Wind Symbol. This actually creates a pulse which has the effect of knocking back foes if they’re within 10 yards of you. This also deals them damage. Once these enemies hit the ground, their movement speed is then reduced for five seconds, and they’ll target a different immortal if available.