An item that is only of use against Titans that extends the battle time for, let’s say, 30 more seconds. (if brought into any other battle, the item is grayed out since it serves no purpose and prevents it from being wasted). The item need not be very rare since it has a limited scope of use.
There are times when my team are right on the verge of killing a Titan, only to have time run out, leaving you unsure if someone else will come along in the last few minutes to do the tiny bit of remaining damage. Sure, a flask can be used to fix this, but sometimes it feels like a waste doing so since they are rare and you may regenerate your energy before using the others on the next Titan.