I have trouble making use of my monsters spawned because they cannot activate in the turn I spawned them, but when its the players' turns, they decimate them quickly and I often will not get the chance to use them at all. If I spawn the monsters far away, they will take turns to reach the heroes, which is usually too late and the final boss will already have been killed.
I understand the monsters newly spawned by an OL cannot be activated until his next turn. But is there any existing card or way that allows the OL to instantly activate his monsters? So far the only one I have seen that can be spawned and activated instantly is the Mimic.