There aint any zod runeword. If the Zod bug still work.(Socket Zod, unsocket item and item keep indestructible.)
It could be useful but nothing great. You would use the bug then make Exile. But it is still a really low % block shield. So, for the rune needed i dont think it's worth to keep unless you would use it as a switch and put some diamond in there to gain a huge chunk of resist when needed.