?( any chance of having belief opposed guilds ie dark and light that will attack on sight as part of the criteria of the guild?

The Chryalis spider is 10 cm when fully active and 4 cm when in its dormant or enchanted state.
It resembles a cut gem and the species of creature it first feeds upon will determine its colour.
When first hatched Chryalii are a stoney colouration and will kill the first creature they happen upon.
The venom used by the spider is magical in nature and will turn all blood to crystal to be ingested by the spider.
The chryalii are used in the manufacture of magical amulets and while incredibly dangerous in the hatchling stage, they can be bound to an alloy developed by the jewellery,alchemy and crystal way devotees.
The problem with these amulets are that they are alive and need to feed upon their users. Taking half of all hits once per week.
The advantage of this is that the amulet will boost the magical, natural or martial abilities of the user depending on the colour of the chryalis.
The spiders only live in areas of high light intensity and will die if not bound to a trelz amulet.
The trelz is electrum in specific proportions treated by alchemy and crystal enchantment all stages of development are seperate and fanatically protected by the guilds.
The chryalii are rare and can only be harvested by species with no internal fluids they have an acidic mouthpiece which will bore through any armour and will naturally drain enchantment.
Due to their rarity life lost and time involved in making these amulets they are extremely expensive.
I give the plane shift team to use this idea as they like and at their discretion