Onderzeeboot
Ecstatic Orb
So... Ill-Gotten Gains was powerful but pretty backbreaking in certain board states. I've had it function as a one-sided Wrath of God + Thoughtseize multiple times. I've been thinking hard about an alternative, but it's pretty hard. This was looks somewhat fun, tough it basically is a tax spell for your opponent's creatures, the activated ability means you might want to skip playing a creature, even if you have the mana to pay the tax, to avoid the token defecting to your opponent's side. You can also activate it for X=1, and see if your opponent bites. Don't know if the numbers are right on this one.