See Hoverbreaker Thug and Challenge # 135. There's limited design space on my concept of Two-Person Con. I designed it flavorfully and so that each card could work on its own, but works well with an additional card.

Also I thought of the idea of keeping friends close and enemies closer. The base card I created to show this mechanic was red, so this car is green. I will make a white card as well.

I like the idea behind this, but you're right that there's some problems too. One of the problems is that you probably need a lot of cards that look like this to make the mechanic work:

Kid Lookout
­
Two-Person Con
­: Untap Kid Lookout
1/3

Which seems fine by me. Maybe there could be an aura that grants tap abilities mini-theme. It does raise the question of "Why not just use Soulbond with an extra line about untapping both creatures in the game text" though. You know... besides the fact that the name 'Soulbond' doesn't sound very thief-like.

Actually the hard part was that I found you have to restrict every tap ability in either how many times you can use it each turn or when you can use it each turn.

jmg: I think you may have misread it. This mechanic doesn't say "both creatures become untapped at the same time", it says "when one taps the other untaps". There's a natural built-in way to tap creatures - attack with them - so this card works plenty well enough on its own. It's just a pity that the restriction means you can't use it to give something +2/+2.