Guild Wars 2

Do two of these stack with each other? (meaning does it give 10% dmg increase?)

Do superior sigil of fire and air a good combination on a 2 handed weapon, after their recent buffs?

Or should i mix match those three for a combination? (Force n Fire? Force n Air? Fire n Air?)

1) No, two Force will not stack.
2) You could use that, for PvE I’m going to prefer Force/Night and possibly Force/Accuracy or Force/Fire, depending on situation.

Thanks for the answer =)