Mark infiltrated the enemy territory to spread poison.
Anne is there to siphon the vitality of their Nature.
Paul was there to make sure that the word about the invasion doesn't spread too far.
And last hut definitely not the least, Raven is also there to make sure that the Abyssal Emperor is cut off from the picture. Suppressing him enough for the Abyssal army to be a headless chicken.
With the four of them working their magic in the enemy territory, there's practically a 100% chance that next part of their plan will go along the schedule. In addition to that, the Dawn Council is also making sure that the Abyssals are distracted in different areas so that these three won't encounter any disturbance in their mission.