Since they are daily's and they can be pretty interesting, it would be good to have a place to talk about them.
There are two Twilight Missions each day. They appear to be somewhat random. You need to have beaten the regular boss of a mission in order to be able to do the Twilight Mission when it comes up in rotation. Doing them yields loot, often of exotic rarity. That's useful, because it enables you to forge perfect gear.
It seems that in Twilight Missions, Revenants automatically spawn randomly when you get close to their graves. I really like it.
As for today's, I was able to do the Level 20 one. The 145 one is still locked for me.
I was actually able to craft awesome dual swords that fit near-perfectly with my style. I like to deal Ki damage and then finish up with a grapple and a combo. I got fire damage, health steal on quick hit, reduced Ki consumption for quick attacks, increased damage on quick attacks, increased grapple damage and a familiarity damage bonus. Sweetness.
Talking about elemental damage, what is your favorite? Mine is probably Poison and Water. Wind is pretty incredible too, but it doesn't fit my current playstyle. Earth sounds like it would be awesome when that PvP gets here.