Flank
When this model would be Deployed, this model's Controller must choose whether this model will use Flank or not. If the player chooses not to use Flank, this model is Deployed as normal. If the player decides the model is using Flank, then the model is left Elsewhere and instead before the game the owning player makes a note of which turn the Flanking models will arrive and notes a neutral table edge: This is Hidden Information. This must be turn 2,3 or 4. In the starting phase of that turn reveal the number and deploy the models anywhere along the chosen edge but not in the Opponent's Deployment Zone. If a model gains Flank mid game or is removed and returns to play using the flank rules, you immediately note any turn (Not just 2,3 or 4) and neutral edge for that model when it is removed from play: This is Hidden Information. Flanking models generate two Activation Counters when they are Deployed.
War Weary states its duration: “In the first turn”, so models coming in with Flank on the same turn will still only get a single Activation Counter.
If a model with Flank cannot Deploy on the Flank turn, they stay Elsewhere until some other trait or effect can bring them back to the board.