Arcana Heart 3/Clash
Clash is a mechanic that has been showing up more and more in recent fighting games. In Arcana Heart, instances of clash occur when two attacks connect simultaneously or if a move with clash properties meets with another move. In technical terms, when two similar offensive hitboxes meet at the same time or when a move with a clash hitbox during its startup meets with an offensive hitbox. After an instance of clash, in the air you can cancel into any attack or movement afterwards. When clashing on the ground the rules are very similar, except that you cannot cancel directly into the same move repeatedly. In Arcana Heart clash is often taken advantage of as an anti-air, i.e. clashing an incoming airborne opponent's attack with a move with a good amount of clash frames then canceling into 5A. On the other hand, there are also moves that will not generate an instance of clash under any circumstance. Kira's J.E or Scharlachrot's chain attacks for example will not clash with anything even if they cross with another move at the same time or meet a clash hitbox. Most Supers and lock moves also do not generate clash.
After clashing with an opponent, you can choose to not "clash battle" with the opponent and guard. If you quickly guard you will not receive a hit from your opponent should they immediately cancel into another physical attack. You can also cancel into highjump after a clash for a highjump guard. This is like a high-chickenblock. If you do it quickly and preform it correctly, you can highjump and block any incoming attacks while avoiding any throws out of clash. This tactic is not invincible however, as attacks that break air guard will still hit you.