In the Lanthanide Series we're talking about the power to assert our autonomy. The kind of power coming from our sense of Self. Our inner strength.
On the right hand side of the Lanthanides we have lost some of our power. With Holmium it could be a sense of previously subdued Power coming to light - and subsequently the Wisdom of learning to deploy Power morally and responsibly. It could also be a sense of having been downtrodden and ignored to the point where we start giving in. Giving way in almost every case. We have just lost contact with the inner resources required to get back on top of things. It all starts to slide.
The power, once awakend can manifest as anger - and old anger turns to resentment. The repressed feelings come out as a rage against the machine... Its exact expression depends on the Salt:
In Holmium Oxy there is anger at injustice and a sense of being wronged.
In Holmiun Nit the anger could be caused by feeling second best. Like Nux-v they want the best - they put themselves first and are assertive, expansive and want to be admired. They dont want rules or limits.
In Holmium Phos the anger or frustration is caused by betrayal by friends and loss of contact. Phosphoricums define themeselves by these boundaries and fear loosing them. This is comparable to the spacey, boundless, gaseous state of the Nitricums (perhpas expressed in the 'polarity' Nitrogenium delusion - everything is meaningless). Phos wants to be earthed to some degree.
Im Holmium Mur the anger is about the grief from deeper relationships - broken trust, neglect or loss of security.
Without wisdom and compassion power gives you the ruthlessness of a dictator, which is traditionally associated with Mercury, in Stage 12 of the Gold Series, the realm of external power. Meurcury feels suspicious and threatened. Thalium, next to mercury in Stage 13 of the Gold Series, trys to hold on to his power by being stubborn and dogmatic. He needs to be stubborn and irritable to get his own way because he has almost lost faith in himself and, more importantly, his strength . He eventually withdraws into himself.
Similarly the pathological Holmium (also Stage 13) has lost faith in his inner self - his own being and is also on the back foot. The remedy brings back some of this lost power.
Looking at my own life I can see a contiunuum of very closely related states that goes:
Dysprosium -> Holmium -> Erbium.
Dysprosium, at Stage 12, feels independent but under constant attack. They are brave people who challenge the world with new ideals. Sometimes they can get such a battering that they feel like giving up. That point - giving up the fight - marks the transition to the next stage Holmium, where they can no longer preserve their autonomy and have to take a step back. This is felt as a heavy deafeat. Hence the bitterness.
In Erbium, (Stage 14) they have really lost the fight. They feel powerless. After that comes the despair of Thulium (Stage 15) a state so dark it would frighten you to even read about it! Beyond that lies dissociation and ultimately - madness :)
Refs: "Elements" (blue book) and "Secret Lanthanides".