The Orisha religions do not have this concept of the 7 african powers of being "the most important" or prevalent Orisha at all out of a pantheon of hundreds, of some who will be more personally concerned with you than others. The Orisha are all received in ritual and pots anyways, or are in your court and not to be used as a group or pick and choose either. The beginning rituals in Ocha, usually is to receive the 4 guerreros or warriors for your own personal growth and care: Elegguá, Ogún, Ochossi and Osun. This does not make you an initiate until you make kariocha with your personal Orisha.
The 7 african powers are spirit guides, dead elevated humans, just like the madamas, or la madama, not everyone has one of these commissions in their spiritual court or cuadro that makes up your spiritual frame.
Therefore there is no reason to be petitioning them or honoring them without this knowledge, as it will weaken your spiritual connection with the guides you actually do have. Despite people making products and writing books that are not in these traditions since the 1980's.
They represent different african tribes, of dead, that one may have, and one will usually take the lead and come through a reading in Ocha or a misa (seance) in espiritismo. No one person will have the same guide that comes through this category. Dr E, a spiritualist, santero and hoodoo doctor identified them as coming from Yoruba, Congo, Takua, Kissi, Calabari, Arara, and Mandika tribes. Within the diloggun oracle’s corpus of information, the Seven African Powers are heavily referenced in the odu Edigbere (7-8). Interestingly, this odu also speaks about the importance of the drum as a tool to call down the Orishas and it also speaks about the power of Congolese magic within the religion of Palo. (however beyond that one cannot comment on Palo or ones spirits within that religion unless being a priest of Palo, but the dead are the dead). It speaks of working with the dead in context of being around the person, which santerismo, palo and espiritismo would be a path open to them being associated with strong dead.
If a person were to receive the odu 7-8, it would indicate that they have the Seven African Powers in their court of spirit guides and it would be up to them to seek an Espiritista to determine who they are, what their names are.
Copied from http://santeriachurch.org/the-seven-african-powers/
I do disagree when he says anyone can approach them because we all have dead. Yes we all have dead, but it is appropriate within these traditions and for safety to go to misa, and work with your dead you actually have first. Its not to say you will have these at all, so its pointless. Can you call forth a dead from each tribe? I suppose, at your own risk with varying results. Would this then be guides as used in the originating culture, or the 7 african powers, no. It would just be working with the dead. And they are usually not ancestors, and guides are mostly contracted and present since birth. The best thing would be to enquire before a misa, or get a investigation or reading.
The 7 african tribes are usually worked with a 7 color candle, and a 7 different color striped or patched cloth. For us in Sanse and puertorican espiritismo, 7 is the number of the higher spirits such as Lwa, enlightenment, the auric field light spectrum, and the celestial energies of planets. In my tradition we do not use the 7 bead pattern of 7 colors necklace. We do use a multicolored necklace from the more congo lineage, as we have palo pracitioners in our house. The multicolor also represent all your personal dead including ancestors, necessary spirits of the dead and guides, not just if you have these 7 african powers in our house. This would be called the egun and the egungun associated with the multicolor dress outfit in the yoruban faiths. This is why Oya the Orisha of the cemetary gate is associated with the multicolor skirt, the colors of the wind and dead, besides her brown-red-purple burgundy and the multicolor stripe skirt of the Palera. 9 is moreso associated with the dead and her number. And we use 9 color bandanas on our white table to the dead, 7 on the divisional table to the Lwa. I have seen one lineage use the 7 color 7 bead necklace sequence for the misterios or Jefe Lwa that a emmisario or messanger dead of the Lwa, but we personally do not do this, and have our own way of making a bead necklace for a misterio, but this is not traditional, nor receiving an eleke as they do with Orisha. In Haiti some hounfort do have necklaces which belong to the temple with a specific number of beads to represent all the misterio for the Mambo or Houngan, or made for a Hounsi if it is known the misterio they are under.
Egun dancing masks, Benin, by Susan Carlslund
The just judge image is used for folk magic such as hoodoo in justice or court case work, usually in a multiple odd number of novena candles. The just judge is Jesus in the protestant tradition, or Yaweh as they are not polytheist as the judge of mankind, or at least the judaic followers. But it is also a mystic glyph of the sun who is the roman glyph of sol invictus, invincible (winning), and of the bay laurel crown (corona from the sun) of success and victory. Jesus's death signified victory over death as soul everlasting, as well as the justice of a new deal over old testament and Mosiac law. As lady justice has been blinded, many turn to court case work to get a fair trial, for forgiveness, against enemies (as the old guard god of vengence), protection from enemies, or a positive legal outcome. Psalm 94 is sometimes used.
Of course there are many different Jesus images, as there are fewer than the assorted Mary's used to represent the higher misterios of the Lwa and Orisha. The crucified Jesus may be use to represent Ogun of war and blacksmith god of making the nails and sacrifice, justice and progress,or Olofi incarnated god, the thorn crowned as power of god as mars, the one of good hope or esperanza as Torolisa the bull Lwa, and the sacred heart as Gran Solier sun Lwa.
The 7 saints usually picture around this is:
- Saint John the Baptist.
- Virgin of Regla.
- Saint John the Baptist.
- Saint Martin of Porres.
- Saint Joseph of Arimathea
- Jesus Christ on the Cross.
- Lady of Mercy.
- Saint Barbara.
- Lady of Charity of Cobre
- The saints are not the Orisha, Lwa, nor the dead guides in question, and saints are used as such in a religious or catholic folk witchcraft, or modern hoodoo sense. As the saints were also not originally in hoodoo, added in since the 1970's. Just Judge, Jesus was used in the protestant sect.
New Revised Helping Yourself With Selected Prayers:
Oh Just and Holy Judge, Blessed Son of the Virgin Mary, let my body be calm and my blood be washed so that wherever I may go, the hands of my Lord Jesus Christ be in front of me. That of St. Andrew before and after me. St. Peter's in the back and the middle. Those of the Virgin Mary, that my enemies may come and go with eyes but without seeing me, with arms but without hurting me, and that justice may not apprehend me. That my body be covered with the cloth that covered Jesus Christ's body, that I may not be hurt, or dead, or incarcerated. Oh Virgin Mary, this prayer I say for good or evil that my enemies hold against me. If any sentence be in this day against me, let it be revoked by the blessings of the Father, the Son, and the Holy Ghost. Amen
During spiritualist misas, just judge prayers and chantry or mass for the souls of the dead are done to the just judge and especially around the day of the dead, after funerals for their benefit, and souls in purgatory.
I hope that this clears up the issue and should not discourage you, but encourage you to find out who your spirit guides are, inform your practice, and further your learning. Use this information to evaluate correct resources and teachers, who should actually be in the tradition you are learning about.