Worst Fears

While controlling another player, you also continue to make your own choices and decisions.

You also can't make any choices or decisions for the player that would be called for by the tournament rules (such as whether to take an intentional draw or whether to call a judge).

You only control the player. You don't control any of their permanents, spells, or abilities.

The player you're controlling is still the active player during that turn.

You can use only the affected player's resources (cards, mana, and so on) to pay costs for that player; you can't use your own. Similarly, you can use the affected player's resources only to pay that player's costs; you can't spend them on your costs.

You could gain control of yourself using Worst Fears, but unless you do so to overwrite someone else's player-controlling effect, this doesn't do anything.

You can't make the affected player concede. That player may choose to concede at any time, even while you're controlling them.

If the target player skips their next turn, you'll control the next turn the affected player actually takes.

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