25% chance to gain a Challenger Charge when you Hit a Rare or Unique Enemy while in Blood Stance
Gain a Challenger Charge when you Kill an Enemy while in Sand Stance
2% more Attack and Movement Speed per Challenger Charge 
Arena Challenger is a notable Ascendancy passive skill for the Gladiator that interacts with Blood and Sand Stance. While in Sand Stance, you gain a Challenger Charge on kill. While in Blood Stance, you have a chance to gain a Challenger Charge when hit a Rare or Unique enemy. Each Challenger Charge grants more attack speed and movement speed, stacking up to 10 times. Charges last 10 seconds and can be refreshed upon reaching the maximum amount (unlike e.g. Divine Charges which reset back to zero).