Lets say Egyptian Magicians blocks, adds a battle winner to battle from the top or bottom. Does the hero have a chance to negate the battle winner before Egyptian magician bands?
Only if it causes Special Initiative.
When a player is controlling character(s) in battle and an opponent's special ability, or a game rule that has been triggered by an opponent's special ability, would leave that player with no character in battle when the special ability has completed, they have Special Initiative. When this occurs, all abilities are paused and suspended (including additional abilities on cards played or any triggers) and the player with their character(s) being removed has the opportunity to play an Enhancement that will interrupt or negate the ability that is causing the removal (or that triggered the corresponding game rule). The enhancement played must be able to interrupt or negate the removing ability. If the card with the removing ability was already removed from play due to its ability, it may still be targeted during Special Initiative by an enhancement that specifically targets its card type.
So if a played card removed all, or the last, of the opposing characters in battle, everything pauses for Special Initiative to happen. Once that ends, then the rest of the abilities (band in this case) occur.
If there are any characters left on the opposing side, then the band happens before anything can be played; there is no initiative nor Special Initiative to allow anything else to be played.
