There are many cards that offer whether you want to take control of one of your opponents monsters, which is actually a +2, because you gain a monster, and they lose a monster. Some examples are...
Big-Eye, lets you take control of one of your opponents monster forever, but it requires 2 level 7's to make, which in some decks, especially Dragon Rulers, is easy to make.
Alien Brain is a trap which can be extremely useful in reptile decks. When a reptile of yours is destroyed by battle with an attacking monster, and sent to the grave, you can take control of that monster, and treat it as a reptile. This is very useful in reptiles, and lets you keep the monster forever. Can be combined with reptile searchers, like Reptilianne Gardna.
Another known one is Enemy Controller, a quick play spell that just requires the tribute of one of your own monsters, and letting you control one enemy monster until the end phase of the turn. This can be very useful with Frog Monarchs, using Treeborn Frog as the fodder.
Your task is to identify 3 OTHER control cards, and explain in depth, the level of control they can provide, how they can be used, and what decks can utilize them, and the restrictions that they may pose. Again, you can not use the given examples.
A 200DP award will be given to the student with the best answer,
Enjoy!