Not so much a “nightwalker” as an “afternoon napper”, but still…
Manny with:
*Susan Grant’s The Legend of Banzai Maguire and The Scarlet Empress
*Kathleen Nance’s Day of Fire
*Liz Maverick’s The Shadow Runners
*Patti O’Shea’s The Power of Two
*Jocelynn Drake’s Nightwalker