Increases this ship's DMG to CLs by 5.0% (15.0%) .
Wolf Pack Tactics
For each Iron Blood SS in your fleet: increases this boat's TRP, RLD, and Accuracy by 1.5% (6.0%) .
All Out Assault Ⅱ
Activates All Out Assault Ⅱ: VIIC-Type Submarine immediately after entering the battle.
Wolf Pack Formation - U-557
Increases this boat's TRP, ACC, and RLD by 1.5% (6.0%) for each Iron Blood SS in the same fleet. When this boat leaves the battle: fires a Lv.1 (Lv.10) special barrage based on the number of hits this boat scored with her torpedoes (DMG is based on the skill's level).
I'm U-557, Iron Blood Type VIIC submarine... I went on four sorties during the war, sinking six merchant ships plus Galatea. The day after I sank her, an allied ship mistook me for a Royal Navy ship and collided with me... I had a few accidents before that too, so maybe I'm just cursed with bad luck...