Hello during the duel with my Fossil deck I special summoned Fossil Warrior Skullking with Fossil Fusion.

My opponent had 3 monsters on the field 2 face up and 1 Set. He had no face down S/T cards. I attacked with Fossil Warrior Skullking and after his first attack destroying my opponents first monster there was no option for him to attack once in a row again nor could I click him and hit and hit Activate an effect anywhere. The monster destroyed was Harpies Channeler and the 2nd monster was Harpie Lady Sisters.

Sorry I hope this was done well enough I checked the post before reading and im still new to this forum hope this was alright.