Worst Fears

Multiple player-controlling effects that affect the same player overwrite each other. The last one to be created is the one that works.

While controlling another player, you make all choices and decisions that player is allowed to make or is told to make during that turn. This includes choices about what spells to cast or what abilities to activate, as well as any decisions called for by triggered abilities or for any other reason.

You can't make any illegal decisions or illegal choices—you can't do anything that player couldn't do. You can't make choices or decisions for that player that aren't called for by the game rules or by any cards, permanents, spells, abilities, and so on. If an effect causes another player to make decisions that the affected player would normally make (such as Master Warcraft does), that effect takes precedence. In other words, if the affected player wouldn't make a decision, you wouldn't make that decision on their behalf.