So these started as random Curses I was going to make in a game thread until I realized they kinda had their own flavor.

Whereas Curses are ongoing effects that make opponents's life difficult, Heists paint a target on their back, marking them for a job that, once done, gives you benefits. In a duel the uses are pretty straightforward; in multiplayer it introduces some political elements where you can use the Heist to dissuade a specific player from being attacked or even as a bargaining coin to make someone else do the job for you (hit the player with my Heist and I do X for you).

Midnight Break-In

Enchantment -- Aura Heist
Enchant opponent
When enchanted opponent is dealt combat damage, sacrifice Midnight Break-In. When you do, that player discards two cards.

Loot the Dragon's Hoard

Enchantment -- Aura Heist
Enchant opponent
When enchanted opponent is dealt combat damage, sacrifice Loot the Dragon's Hoard. When you do, create three Treasure tokens.

Assault at the Nicily Precinct

Enchantment -- Aura Heist
Enchant opponent
When enchanted opponent is dealt combat damage, sacrifice Assault at the Nicily Precinct. When you do, Assault at the Nicily Precinct deals 4 damage to that player.

Commercial Espionage

Enchantment -- Aura Heist
Enchant opponent
When enchanted opponent is dealt combat damage, sacrifice Commercial Espionage. When you do, create a token that's a copy of target permanent that player controls.

Interesting. In 1 vs 1 they're just situational spells. But in multiplayer they make attacking your enemy a tempting proposition.
There was a supplemental product CKY designed with a similar mechanic and identical name. viewtopic.php?f=17&t=9334

By calling them Heists you kind of restrict yourself to the combat-damage trigger. It seems like there's a lot of design space in other triggers too.