Just as with the Weapon Challenges the gear challenges for each javelin are also quite similar. All you have to do is play a total of 4
missions or world events with specific abilities equipped on your Colossus javelin. Note: Entering and leaving Free World does not count.
You can track your progress by pressing
, then browse to Challenges -> Gear -> Colossus
. Select the ability you want to track and hit
The 12 Colossus gear challenges required for this achievement are:
Siege Cannon I
Firewall Mortar I
Shield Pulse I
Burst Mortar I
Venom Splitter I
Battle Cry I
Flak Cannon I
High-Explosive Mortar I
Lightning Coil I
Shock Coil I
The abilities drop in the world or in any mission, but only if you have the correct javelin equipped while you look for them. This isn't as bad as it looks as missions are completed in 10 minutes and you can equip 3 abilities at the same time.
The fastest way to level these up would be to go to Freeplay with coop partners. Take off in different directions and let each other know when you found a world event, then join up. World events can be completed in under 5 minutes and will count toward the challenge. They can easily be done solo as well (set the difficulty to easy if you have to) but can sometimes be a bit hard to find.
If you're doing this solo then I recommend combining this with the Explorer achievements for maximized efficiency.