Forum:Attack vs effect

ok, it was my friend's turn and he was in his battle phase, and my skilled dark magician had 3 spell counters on it, he played heavy storm, i activated MST, and so did he, so he attacked my skilled dark magician [with 3 spell counters], with his elemental hero neos alius. so, i said to him i use my SDM's effect to SPECIAL SUMMON MY DARK MAGICIAN while he was saying i attack ur SDM[with 3 spell counters]. now, can i or can i not SPECIAL S"UMMON my dark magician if it is on my friends battle phase.???