Diamond

Diamond one of the rarest material that exist in Terra as not only it is a precious crystal that is pretty to look at, it hold the energy that is needed to connect it to the lay line which may make a spell caster who have the spell like revivify to connect their spell with the help of diamond as the material to bring back someone from the hand of death of course with this diamond is in high demand but diamond can only be found in the Lost Isles which is located in between Vallarian and Titanfall if someone would try to find diamond in Terra but if they are able to access the astral sea diamond can be found in other planets or in lost bastion of wizards of the past which have started to collect this diamond which hold such magical capability that may bring someone back to life and also to tap into the lay line it self which allow a caster to bring a soul from the other realms back in the world it self unless that soul decided to not want to go through the lay line that was created by the caster.

Diamond Magical Property :

Diamond it self hold the magical unknown property of connecting to the lay line it self making it the only material that is within the known multiverse that is well known which allow someone who have them self knowledge or the capability of magic to bring someone back from the death as the diamond will allow the caster of that spell to open a gateway where the soul of the creature can return back to the body of the creature, but of course not all spell or power can bring them back from the death as sometimes the soul it self doesn't want to go through the gate way within the lay line due to their own reason, but still there are several other reason why diamond are not able to bring a soul back which may be from the realm where the soul is currently residing in is not able to be access easily which is rare due to most souls within Terra going to the realm or place where the god or goddess that they believe in go or they might just go to the nine hells if they don't have any where place to go and also evil in nature or other realm within the known multiverse which all of the known realm that can be access by someone who is powerful enough within the known multiverse can bring someone back to world of the living.

Diamond it self can bring normal mortal kind back from the death from a spell like Revivify or Raise Death, but not any known spell can bring a strong creature back from the death like gods or demi-god where they have too much of a powerful than even a powerful mortal that bringing them back is something that will need a bigger, that the diamond are not able to do even if there is a spell for the creature that is that powerful.

Diamond Within Terra :

Diamond within Vallarian are non existence as some people have tried to look for it in Vallarian and they have not found any yet even if Vallarian is a huge continent and also the already high amount of technology and arcane art that the people of Vallarian have developed to help finding this rare material, most people in Vallarian have give up on finding diamond on Vallarian land and some of those decided to trade with the people in the Lost Isles and even some of them decided to open a mining operation in the Lost Isles it self as it seem like to only way to find diamonds easily without going to the multiverse it self which the start of the connection between Vallarian and the other realm have started after the Calamity Event as some guilds and nations started to build gates or portal to the other realms so they can easily travel through each other which also causes some people to think that they may able to start finding diamond in other realm but this operation have not actually fully started as the other realms government are not actually truly in control over all of their territories as within their realm there are mystical creature and also other normal creature who may not follow the order of the realm governments or they may just be not able to understand their governments as language different or it may just be that they are animal/beast which is not able to understand the order that the people of that realm is telling them, as the people of Vallarian notice that the other realm is more dangerous than Valla which within it self have developed to not have dangerous creature anymore which is related to the history of Vallarian not really having a lot of those mystical creature it self due to Valla being created by a bunch of demi-gods who escape from the Titanfall Isles Trial.

Impact :

Diamond hold a bunch of historical impact as it was being use by several different people within the multiverse it self using diamond to intervene with the lay line it self for example to bring someone from the dead or using diamond to empower a spell it self as diamond is connected to the lay line, making a spell which is depending on the connection to the soul or energy of the world it self  even more powerful than usual, or the diamond it self have a impact where someone who is important within the multiverse was risen back up with a spell like revivify or raise undead which allow them to continue living until their natural death of their mortal life which have a lot of impact to most government or any sort of group that may have a disaster or a war that is happening that may cause they person death.