So you think Rek'Sai has no utility outside her knock up?
I tested a few things on Rek'Sai's Tremor Sense and her tunnels in custom games with my friends. Basically,
- Rek'Sai can Tremor Sense stealthed units! Can you say Shaco counter any louder? Obviously, this is only if the enemy is moving.
- Rek'Sai can still use her Tremor Sense to its full capabilities during an enemy Nocturne's ultimate!!
- If an enemy steps on one of Rek'Sai's tunnels, the minimap icon disappears immediately even if you don't have vision of the tunnel!! So as long as you can keep track of them and keep an eye peeled on the minimap, you can have up to 8 pseudo-wards on the map!
I wonder if the third one is intentional. I feel like Riot might not want to make it intentional since jungle monster icons don't work that way, but then again, Rek'Sai does need to target these to ult to them, so not being able to ult something on your minimap might be weird. Anyway, happy Shaco/Nocturne hunting as Rek'Sai! 
