how to duel a marauder :
They force charge.
You uppercut and jet knockback...they should be slowed. You'll take some dmg...it's fine.
As they land you can hit a tracer if you are fast enough and they dont stealth right away.
They will stealth. DROP STEALTH DETECTION FAST. i always win if this is dropped on them.
(IF they don't stealth, keep spamming missles until they get close again.)
Pop unload.
When they get close, pop dmg reduction shield and strafe a bit away along with kolto healing.
Now they should be in melee range. Trade hits.
Uppercut should be back off CD. Upper cut again and trade powershots/tracer missle. It's fine if it gets interuptted. switch to other one.
If they're at 50% this phase or less, easy win...they should be around 70%.
When jet blast comes back up, use it...this will put their CC bar at 90%.
This time, they have no stealth and are slowed. 1 or 2 more tracer missles/1 unload for snare.
(sometimes i instant cast fusion missle here too)
At any point in time they use their CC break, u hit stun after. And drop a free cast death from above if you can do it quick.
If they do their low hp thing...tracer dart and run
You CC break force choke at any time. And give them a missile during their channel animation after breaking it..
You vent heat when needed.
You haven't used your instant cast cooldown (save for heal)
Chose when to use heatseeking missles and railshot.
And remember, u can't beat a marauder by kiting, you have to trade hits with every little distance you get.
(2 piece eliminator set is a must!)
Hope this helps.