The Reflex Badge allows for a bonus when a Reflex Card (denoted by the symbol in the bottom-left corner)is played. Some cards also only activate their effects if you have the Reflex Badge. You can earn a Reflex Badge by choosing Non-Stop as your class, or by investing in the Reflex Badge as another class.
LoH ReflexBadge

The Reflex Badge

Badge Effects:

Acolyte:

Rank 1: 5% chance ally cards you played are unstoppable

Rank 2: 10% chance ally cards you played are unstoppable

Rank 3: 14% chance ally cards you played are unstoppable

Rank 4: 18% chance ally cards you play are unstoppable