One can use Tan Da, Pak Da and Bil Da as a defensive technique. But I for one love to use it as an offensive entry technique. I Pak Da or Tan Da my opponents guards, punch or grabbing arm as I move to a flank or inside. Using it offensively gives you advantage because you are taking the fight to them. To use it defensively you have await the opponents attack. Patience is a great thing.
The Flow is relentless like a raging ocean with crashing waves devasting anything in its path.
"Kick Like Thunder, Strike Like Lighting, Fist Hard as Stones."
"Wing Chun flows around overwhelming force and finds openings with its constant flow of forward energy."
"Always Attack, Be Aggressive always Attack first, Be Relentless. Continue with out ceasing. Flow Like Water, Move like the wind, Attack Like Fire. Consume and overwhelm your Adversary until he is No More"