The Four Eights are attributed to Hod (eighth Sepiroth--Splendor) on the Tree of Life. Since Hod is in the same plane as the Sevens (Netzach-victory) the same weaknesses and/or defects that are in the sevens will apply. Yet, in a sense, the alleviation of the Sevens weakness is also being applied in the Eights. One might say that the mischief has been done and their is an action against it---much like white blood cells attacking a intruder in the blood stream; not a total cure but a beginning in that direction.
The Eight of Wands is called SWIFTNESS,and it is attributed to Mercury and Sagittarius making it Swift indeed! This is the ethereal (invisible) aspect of pure fire where all gross-material aspects are removed. Fire is no longer conjoined with ideas of combustion and incineration. In the 8 of Wands, fire is represented as energy in its most exalted state and suggest electrical current and/or pure light in its material sense. Sagittarius represents light as the rainbow and that is shown on the card, as well as electrical current being shown as lightning bolts, throughout the "as above so below" design of the cubed diamond.
The Eight of Cups is called INDOLENCE, and is ruled by Saturn. Saturn's rule imposes time and sorrow onto pleasure, making a general unpleasantness. There is no strength in the element of water to oppose this unpleasantness. It is almost like a hangover, except the party never happened as the caterer has not brought the "good cheer" nor has the host invited the guests. this card represents a fault of the host, whose plans were beyond his/her capacity to meet. The Eight of Cups usually means that great plans where fantasied but the host lost heart at the last moment.
The Eight of Swords is called INTERFERENCE, is attributed to Jupiter and Gemini. Jupiter is genial and optimistic where as Gemini is an airy sign of the intellectual. In the world of swords, this "good nature" will not work. Swords require a swift knock-out blow, if one is required.. However, Eights are Mercurial, and unforeseen bad luck abounds. Trivial incidents occur and even in the operation of Great Nations, trivia events destroy the best of plans. The Eight of Swords implies that the error of cancer has been seen, but by being so happily optimistic, the Querent doesn't cut out the cancer....thinking that it will heal on its own. The Querent here, is interfering with their own ability to act.
The Eight of Disks is called PRUDENCE and is a great deal better than the eight of swords or the eight of cups. This is because in the purely material world of Disks, and in money matters, there is a certain strength gained by doing nothing at all. Sometimes, "putting away for a rainy day" is best. The Eight of Disks is attributed to the Sun in Virgo and is the card of husband-man and/or husbandry. One can sow the seed but do little more than sit back and await the harvest. As in all eights, a certain amount of calculation is suggested, and it the Eight of Disks this is not necessarily a noble idea as it is like fixing a fight and then betting on the outcome. This is a very congenial person, on the outside, but who is no- bodies fool on the inside. Practicality with a hint of villainy. However, if linked up with "higher" cards, this is the impeccable path of a Master, who takes their development seriously and examines each step, with out haste. In the realm of matter, a master craftsman comes to mind.
Thank you for your interest and comments. May you live long and prosper!