A single conditional curse, housing a very simple effect with complicated mechanics surrounding it!
Restless is a constantly incrementing curse which prevents you from sitting on a bench. Trying to sit will still set your respawn point there, though. All benchwarps unlocked become temporarily locked until the curse is lifted, and respawn warping to your most recent bench will spawn you off the bench like it does with the Crystal Guardian bench if you try to warp to it.
Now what decides you have the curse? Simple: A number. Picking up Restless curse items will add 500-1000 points to this number. Sitting on a bench, standing still, or being in any menu will also increase this score passively by like 1 point per second. Benchwarping increases it by 200. The score will not increase in the title screen or file select, but you will be penalized with a benchwarp when you load back in.
In order to clear the condition, you must do multiple of the following to reduce the number by their respective values: hit enemies for -3, kill enemies for -10, kill bosses for -50 (Excluding attunement in the hall of gods. Pantheons are fair game, though!), clearing checks for -30, and moving around (-0.1/s).
Here's the fun part though - This value can still be reduced even when the curse isnt in effect! This means by playing the randomizer fast and violent you can nearly completely mitigate this curse altogether by dropping it into the negatives, rewarding routing on the fly instead of while looking at a map.
This curse would help reward players for thinking and routing on the move, as well as give motivation to attacking enemies that you already have extended journal checks obtained for. It also fills a niche of being a curse with a task that isn't outright degrading to the experience. I also think more curses like this which require constant management would be great, but this is the main idea for one that stuck out in my head as being a must have.