Board Thread:Questions and Answers/@comment-28471956-20160526184703/@comment-5780397-20160602180446

If it wasn't mentioned already, there is also the fact that the explosion can be charged. To charge an explosion, Chrollo must touch the person or object on which he is affixing the plus or minus seal for 3 to 5 seconds.

However, it is not clear if both seals need to be charged for the explosion to reach full power, if only one of them needs to, or if the blast is the sum of the power of the two explosions regardless of how long the signs have been charged for.