Life Burst (ライフバースト Raifu Bāsuto) is an ability type found on SIGNI and spells, located under the rest of their abilities. A card's Life Burst ability is triggered whenever it is crushed as a Life Cloth and sent to the Check Zone. After the Life Burst ability is used, the card is sent to the Ener Zone. Life Burst abilities can be used regardless of the card's limiting condition.
Using a Life Burst ability is optional.
Effects that cause cards to be unaffected or untargetable (through Shadow) by a subset of cards will also be unaffected or untargetable by the Life Bursts of cards from that subset. For example, Zhao Yun, Blessed General, which has Shadow-Level two or less SIGNI, cannot be chosen by the Life Bursts of your opponent's level two or less SIGNI cards.
During deck construction, a deck can have up to 20 Life Burst cards. (This requirement was originally exactly 20, but it was changed with Diva Selection.)