Sub-weapons are secondary attacks that consume hearts. You can only carry one at a time, and they are found by destroying candles or specific enemies. Each sub-weapon has a unique effect and an associated Item Crash, a powerful special attack that consumes a large amount of hearts. Richter's sub-weapons include the Axe, Holy Water, Knife, Cross, Stopwatch, and Bible. Maria's sub-weapons are the Doves, Cat, Dragon, and Turtle. Choosing the right sub-weapon for the situation is a core strategic element of the game. For example, the Cross is excellent for bosses, while the Stopwatch can bypass difficult platforming sections.
