I’ve done a lot of research into it so far but I know much more on this journey is required and I’m relatively new to all this.. if there are any experts out there who would like to share some friendly advice etc., please don’t hesitate.
I think that every 8th house stellium is as unique and individual as a natal chart is. And that one can't be compared to the other.
I don't have one - but I've looked at a lot of charts of people with this constellation and talked to them. And can share my personal insight - I have and what I've learned and know about..
8th house as the traditional fix sign water element scorpio house in zodiac - is always delivering very intense and persisting plutonian energy. Even if due to individual birthtime another sign and another ruler falls in 8th house - the zodiac scorpio/pluto energy and house meaning- always remains and stays below and all planets in 8th house are added with pluto energy.
8th house is about a lot of matters - and as it is also about long term relationships, friendships and marriage - as a fix sign following the cardinal sign libra in 7th starting a relationship - one can't easily escape here.
And after having once connected together with another person and this own strong energy - one is willing to persistingly follow it up - not giving up easily - following an inner instinctive flow and plutos' special rules and laws - mostly working under the surface and often beyond personal control. With 8th house placements all can get easily a question of life or death - all or nothing - black or white- mostly nothing in the middle.
8th house scorpio- pluto ruled is as higher principle is about preserve one's own species. The power of being willing to give up own life to save the life of own children.
8th house among others is offering as a transformation experience level - house of death and near to death experience in own life - also figuratively. House of shocks, trauma and life threatening events, the psyche, subconsciously stored memory from the past - mostly the bad ones. House of deep transformation experiences to go up to own limits and beyond- house of addictions, obsessions, sex, crime and rituals. Access to the otherworld behind the curtain - to magic and to the occult.
And 8th house is about genetic heritage from bloodline ancestors, heridated skills and gifts from family members, vows, agreements in bloodline and what one feels bounded to -predisposition for health issues and family traditions, dogmata and beliefs - one has grew up with and one was subconsciously shaped from.
In 8th house one can find passionate true love - even beyond death, karmic relationships - attracting and encountering people one knows from another life before - if one believes in this.
And this is why persons with 8th house placements are not easy to be told from the outside - they only decide on their own- what they feel inside and see as right for them - and have a lot of energy for going their own way and in a way others can't understand - if they don't have this energy available in own chart.
If cap is in 8th house - this in general means- very high standards of perfection one has grew up with and was early expected to fullfill - no matter what it charges - emotions and weaknesses not welcomed and not accepted. But surely it also depends on - where ruler of 8th house is placed and aspected. As 8th house ruler decides on all planets in his house the rules and how it has to run.
Always better to see the chart and the whole picture working together.