Completed grid:
6a.
6b.
MOASMOAS
6c.
ASPSASPS
6d.
SEW
7a.
PRESET
7b.
ETONETON
7c.
NIX
8a.
SEA
8b.
AISLE
8c.
LEIGH (_l eigh_, also Jennifer Jason Leigh)
9a.
GUNS
9b.
SNIDE
9c.
DEERDEER
Inward 1–5a.
PERSONA Column 2
1–5b.
EMPIRE Column 5
1–5c.
VERANDA Column 3
1–5d.
UPPERS Column 2
1–5e.
RAMPAGE Column 1
1–5f.
EXTREMES Column ?
1–5g.
DEMONS Column 4
1–5h.
REIGN Column 5
1–5i.
AGENT Column 1
1–5j.
MONSTER Column 4
1–5k.
NEVER Column 3
Which gives us:
EXTREMES as the hint for which letters in each column to read, and we do so to get: RUNDETAARN