What you mean? Which blocks? (besides the wand of equivalent exchange )
I use these to protect my gate and to "airlock" any new area I'm digging tunnels into to place fence for an enderquarry. If I trigger a bunch of hellfish I just run back behind the stones of warding and kill them safely from range.
Adonis0 replied while I was posting this, oops.
Maybe we shouldn't be posting stuff like this, giving Jadedcat ideas about what to remove from the pack!