Here is a suggestion for an element that makes excellent bunker material:

Titanium-Vibranium Alloy (or TTVB):

TTVB combines all the desirable properties of TTAN and VIBR and leaves out all the rest.  Here they are:

TTAN:  TTVB blocks all pressure like TTAN.  But it does so, even when the line is less than 3 pixels wide.  It also does so, even when conducting electricity.  And it's ACID-proof, unlike TTAN.

VIBR:  TTVB absorbs all energy particles--even protons--and is immune to BOMB like VIBR.  It's tmp goes up as it absorbs energy particles with a maximum tmp of 1000; at this point, it will have a life of 750.  But; unlike VIBR, it's tmp does not rise with temperature or pressure, it's immune to DEST as well as BOMB, and it does not explode.  Instead when it reaches a tmp of 1000, it will no longer conduct electricity and will instead spark nearby electically conductive elements until it's life reaches 0; at this point it will return to it's normal state and go back to conducting electricity instead of generating it.  TTVB's life will not go down if there is no electrically conductive elements close enough for it to spark.

Creation:  It can be made the same way all elements are made; via brush, console, etc.  As you might've guessed, you can also make molten TTVB by mixing, molten TTAN with molten VIBR.  This only works under pressures of 21+ as to avoid breaking saves.

Uses:  Excellent bunker material and solid rechargeable battery.  It's charge is stored as life, as mentioned above and, unlike LITH, it cannot be overcharged and thus does not explode from prolonged charging.

EDIT:  As to prevent future wall challenges from becoming too challenging, I've thought of a new feature.  Once molten TTVB is solidified, it can't be melted back into molten TTVB except by LIGH; just like HEAC.  Same is true with brush-spawned TTVB.

@jacob1 (View Post)

 I probably should have specified the elements that can destroy it.  It's can be infected by virus (solid, liquid, or gas,) and it can be destroyed by SING (but not the negative pressure produced by SING,) AMTR, CRAY, and DRAY.  Of course, any one could forbid the use of the elements in a wall challenge, but perhaps we could make it so that TTVB melts into LAVA but only upon contact with LIGH, just like HEAC.  I'll append that to my suggestion above.

@Asomion463 (View Post)

 I said the mixing of molten TTAN and molten VIBR needs to happen under pressures of 21+ to make molten TTVB, which will prevent the breaking of saves.

@suibian (View Post)

 What would that do?

@thecodeadd (View Post)

 Are you talking about TTVB or VRB(TTAN)?