It's a blue sorcery that wants to swap the affected player. For ex: cast it targeting opponent's angelic chorus to make you gain life. Or cast it on Abyssal persecutor to exchange it for "your opponent cannot win the game" and "you cannot lose the game".
It's an attempt to make a blue sorcery that rather than make you gain control over a permanent, it swaps the affected player. It can be used two ways, cast it on a permanent that you control to have the drawback affect the opponent. Or use it on opponent's permanent to gain the beneficial effect without gaining control over the permanet itself.
How do I word that? Does it conflict with other cards?
The biggest problem here is that the effect that you want introduces a major constraint into card design. Donate is a card very similar in spirit to what you want to achieve, and Mark Rosewater considers it one of his design failures.
It's an attempt to make a blue sorcery that rather than make you gain control over a permanent, it swaps the affected player. It can be used two ways, cast it on a permanent that you control to have the drawback affect the opponent. Or use it on opponent's permanent to gain the beneficial effect without gaining control over the permanet itself.
How do I word that? Does it conflict with other cards?
Article here.