Raiding The Myriad Castle
Mark was going to enter the Myriad Castle now that its defenses were so low and take over the entire fortress on his own. Mark knew this would obviously alert the Angels on the island to what was happening, but by then it would already be too late. And if the Angels on the island split up to try and return to secure the castle, that would give the demons behind them a chance to attack the defenseless deserters and gain the upper hand.
It was obvious that the plan was not completely foolproof, but after only two days, it was the only plan Mark could think of that would give them a high chance of victory. Mark knew he was strong enough to handle hundreds of soldiers if he really went all out, but if there was an SS tier in the castle, or maybe even someone stronger, then it would be a lot more difficult for Mark to take control.
Splash!