User blog comment:Qwertyxp2000 the second/Balance change suggestions for Version 20.0/@comment-32164452-20200720100120/@comment-45290014-20200811081747

I reckon it'll be cool to add a ghost tower for co-op, to be used to recommend tower placements for your teammates. It can be any base tower, can be placed in other players' zones (the tower must still be in a legal position), and teammates can directly place on it easily (either through the ghost's tower menu or placing the tower onto it) or can simply hide it. Only one can exist per player, and anyone can use it to place a tower (provided you can place towers there). This'll help a lot when it comes to working with teammates to optimise defense. The ghost will take no money to place and will not interact with the defense in any way.