Just a ship idea (idk what expansion it would be in)
-Enemy doesn't see it phase jumping. (Even if they have monitoring researched!)
-Ship has some cloaking device, can't be physically seen by enemy in their grav-well (or on sidebar)
-Could be a new capital ship perhaps, with a stealth/cloak ability that lasts awhile.
I realize Vasari scout has an ability like this (Phase Cloaking) but it's kind of not exciting and they still know it's there!
A spy capital ship like I mentioned would add more thrills in my opinion! Be like, oh damn where'd that Space Sub come from! To counter there could be a new logistics or military building (uber sensor building?) that can detect them and/or a sensor cruiser.
EDIT (Missed a sentence ) TEC one could look like a modern, but huge,submarine (their carrier looks like a modern one so hey?) and have more weapons woo.