Dhāraṇīs are special mystical-invocations used to provide spiritual-protection for its recipients. The ones encountered in chapter 26 are meant to protect the teachings of the Lotus Sutra and its devotees. Herein we find many diverse beings uttering dhāraṇīs, from Bodhisattvas (like Medicine King) and even from rākṣasīs. The following is one uttered by Vaishravana, protector of the world:
A ri, na ri, to na ri,
a na ro, na bi, ku na bi.
Through this invocation Vaishravana vows to protect all teachers of the Dharma, and utters, “What’s more, I myself will protect those who embrace this sutra, so that within a hundred leagues no weakness or illness will come upon them.”
(2008-11-10). The Lotus Sutra: A Contemporary Translation of a Buddhist Classic (Kindle Locations 5465-5466). Wisdom Publications. Kindle Edition.
For Nichiren, reciting the title of the Sutra is meant as a powerful Dhāraṇī:
In Nichiren’s teaching, chanting the title assumes a twofold efficacy: it ensures both the attainment of perfect enlightenment and also protection from harm as well as other kinds of worldly benefit. Nichiren’s emphasis on the practice of reciting the sūtra’s title, which he developed over the course of his career, brings together the Lotus Sūtra’s own teaching on upholding the sūtra as the path of attaining enlightenment and well-established thinking concerning the power of incantatory phrases (dhāraṇī) to bring about worldly benefit.
(2010-06-01). Readings of the Lotus Sutra (Columbia Readings of Buddhist Literature) (Kindle Locations 5328-5331). Columbia University Press. Kindle Edition.
The following Nichiren chant from Nichren followers on YouTube of the Daimoku is truly a most powerful form of dhāraṇī. One is encouraged to utilize this as part of one’s own meditation regimen.