Here is exactly what the does (based on current patch data):
While not an official SNK term, "ECM" in fighting game reviews typically refers to high-level movement techniques that allow a character like Zankuro—who is traditionally slow and lumbering—to bypass standard movement limitations. This often involves buffering movement inputs during other animations or using specific "moving" cancels to maintain pressure.
The exclusive card’s effect increases Ultimate damage by 45% if you have moved at least 15 meters in the last 5 seconds.
While the standard ECM skins focused on agility (Chou) and magic (Kagura), the ECM Zankuro skin pivots to raw, devastating force.