Hello, I will try to elaborate the question on my own example. I have the 2nd house start in Pisces, but it incorporates all of Aries. Similarly my 8th house starts in Virgo and incorporates all of Libra. Does that mean that Mars and Venus are co-rulers of those houses or just Neptune (Jupiter?) and Mercury?
Also if my MC starts at 29th degree Scorpio is it still a Scorpio MC?
Link to the chart
Your question concerns intercepted signs. Aries and its opposite sign Libra are intercepted. Intercepted signs come in pairs, of two opposite signs.
The rulers of your 8th house is Mercury, with Virgo on the cusp. The rulers of your third house are Jupiter (traditional) and/or Neptune (modern) with Pisces on the house cusp.
Venus and Mars, while rulers of Libra and Mars respectively, do not rule any house cusps.
Then the moon and your sun are both in intercepted signs. Note that a planet belonging to a sign that does form a house cusp is not intercepted.
Interceptions are possible only in quadrant house systems like Placidus, where house systems are of varying widths. You won't find them in the whole signs or equal house systems, where each house is exactly 30 degrees.
I don't think that intercepted signs have a lot of meaning if they don't have planets in them. An intercepted planet, however, is sort of "boxed in" and may not get a lot of traction in expressing its tru nature. For example, your Aries sun may be more subdued than is typical of this feisty, independent sign.