Scorpio
What is already familiar, instinctive, and ready to be carried forward.
Sagittarius
What is arriving, stretching the old shape, and asking for a new response.
A cusp is best understood as a threshold image: Scorpio's water fixed quality meets Sagittarius's fire mutable quality. The Sun is still in one sign at a time, while the neighboring symbolism can describe the season around it.
Scorpio brings
Scorpio is ruled by Mars and Pluto and speaks through water fixed movement. Its familiar lesson is about the alchemist.
Sagittarius arrives
Sagittarius is ruled by Jupiter and changes the texture toward fire mutable expression. Its invitation is to practice the explorer.
A boundary, not a loophole
If you were born near a sign boundary, use an accurate birth time and place when a precise chart matters. The cusp language can be a useful metaphor, but it should not replace the actual Sun sign.