Guild Wars 2

Currently, I have 1399 Condition Damage and 85% increased burning duration. I am wondering what sigil would be more useful. Sigil of Corruption or Sigil of Malice.

I am already using Sigil of Smoldering. I feel like both would be useful but which would be better.

Would 250 increased condition damage when I have max stacks for corruption be better than an extra 10% duration? But that would also mean killing 25 creatures beforehand.

When I am using all of my skills I am doing about 7k dps. I feel like my damage would go up a lot but with the extra 10%, it would be permanent and I may get another full damage hit from it.

And would conditon duration stack with burning duration? Would I get 95% burning?

Go with Bursting. Flat 6% increase.