OK agents, here's your early notice for the upcoming global event. This GE features a "rock, paper, scissors" of sorts of three of the elemental types in the game:
Deal Burn, Bleed, and Gas elemental effects to enemies in addition to normal damage. Reload your weapon to change the damage type.

For those who haven't done Survival, or are struggling to finish it, this one in my opinion is either the easiest, or 2nd easiest GE modifier to help in Survival. This is especially helpful for the hunters. If you use smaller capacity, quick reload weapons, it is possible to have enemies affected by each element type. In survival, I usually run with my preferred main weapon on Burn, 2nd on Bleed, and sidearm on any of the 3. I think they are listed in the order of effectiveness in there but that may or may not be the case elsewhere.

GE Onslaught:
Starts: September 23rd: 8:00 AM UTC
Ends: September 30th: 8:00 AM UTC

Classified Gear Sets for this GE:
Classified FireCrest
Classified LoneStar
Classified Predator's Mark
Classified Reclaimer

The Playlist includes:
Warren Gate Power Plant
Police Academy
Broadway Emporium
Russian Consulate
Stolen Signal

Modifiers for Onslaught:
Global modifier (always active in all areas of the PvE world):
Deal Burn, Bleed, and Gas effects to enemies in addition to normal damage. Reload weapon to change the damage type.

Savage Onslaught:
Onslaught behavior, enemies are vulnerable to one effect type and resistant to others. Agents take increased damage from resistant enemies.

Brutal Onslaught (Only active while in a group):
Savage Onslaught behavior, plus when two or more group members kill a vulnerable enemy within two seconds, each member can reload to gain a damage bonus for a single clip.

Masks include:
Ember Mask - Kill Count - Kill 5 enemies in a row with the effect they are vulnerable to.
Oni Mask - Full House - Burn 200, Bleed 200, and Gas 200 enemies during the Onslaught event.
Smiler Mask - Never Enough - Complete all Events in the Onslaught Playlist (I read where Stolen Signal was no longer required but it was when I did successfully get it on my primary account. If you don't like that mission, you might want to do this one last just in case.)

Patches include:
Blast Off Patch - Your Weakness is My Sweetness - Kill 100 enemies using the ammo they are vulnerable to.
Bullseye Patch - Light 'em Up - Burn 5 enemies with a single clip.
Falcon Patch - Smarty Pants - Shoot 150 enemies with Smart Ammo.

This is the last GE I need to complete for my 2nd account. When this one was out last time (February if I remember right) I had just barely leveled up to the end game on this account so I only got some of them done. Due to the way Smart Ammo works, a lot of the commendations require an active group. I won't be able to use my two accounts to do the group ones myself. My main account I had all these done the first time they were offered but I had a good, full group back then. If you are on PC and want a team mate for the GE (or longer perhaps) my 2nd account is bambihunter71

*This info was assembled from various sources on the net, I just cleaned it up for readability (hopefully) and posted it. But, after posting it, I realize all my formatting and indentations for readability don't show up on the actual post like it does in the post view. Well, I tried.