Does Fear Offset Threat?

I was on a team with my Kin defender this past weekend with a Fire tank who was using the Quicksand and Burn combo, mostly to very good effect. However, I seemed to get aggro a lot more than I would have expected - it seemed as if once the mobs got out of the Burn patch, they looked up and saw me hoving nearby and went right after me, even though they clearly had been within the Tank's aggro zone before.

So, does the Fear component of Burn cause a reduction in threat to the AI, and thus loss of aggro control?

To get out of burn patch and look for someone else..possible. Blazing Aura doesn't have an autohit taunt. To run out of Burn Patch yet still be in quicksand and attack you, that's interesting. What was his secondary and what were you fighting?

Kinetics toons have a way of stealing aggro called Fulcrum Shift + AoE attacks. Every tank I have looses aggro to kins to some degree. I don't know if it is possible to offset the loss of aggro by perhaps using more taunt IOs or not.

FS is the main culprit and it may even be generating too much aggro perhaps ?

There is no taunt component to Burn. With my Fire/Fire I use the smaller AoE then burn and then the larger AoE to keep aggro as well as get mobs in burn for most of the time. I also find build up an absolute asset to the beginning of the fight duration so my effects are highly likely to hit. You might recognise that with some enemies, the fight groups differ, so build up isn't needed every group, just more so in some groups than others. But lazy me has taunt too.

Fiery Aura/Dual Blades, not an easy combo..considering a basic one needs to actually hit with blinding feint for tohit buff, and it doesn't auto hit with anything but taunt you are more likely to get strays attacking team mates. Stray NPCs aren't a bad thing really unless its particularly dangerous to someone ie a Void Hunter free to get a kheld.

When I am using burn, there isn't a fear effect, it's more of them just getting out of your attack. I don't see ANY decrease in holding aggro. I also feel that I hold aggro better than most tanks out there because of my AoE bombardments of Fire sword circle, combust, burn, and the single superior attack Greater fire sword.

With the amount of taunt I have going; auto taunt and blazing aura, I don't lose aggro, so maybe it was the particular tank itself. It was said earlier that burn does not have any anti-taunt effects and that is true. If you have aggro, when the enemies run out of burn, they should come back. Burn also only affects 5 people at a time.

DBs might be what's hurting this particular tank the most. He didn't choose a really healthy combo but I do know that DBs is one of the most common resisted abilities out there. So it could be that burn was hurting him in the way it was getting things away from him and that they weren't really bothered by him. Do we know what enemies you were going against?

I'm not sure what Dual Blades would have to do with aggro. It's a perfectly fine set for a Tanker, and you can keep aggro with it fine if you use it right. But if you don't make good picks for your primary and secondary, or use them well, you could have issues.

For any Tanker, you want to have your aura going and be attacking frequently. You can go without Taunt, but it does make it easier to keep aggro and makes it less needed for you to run after mobs.