The Diamond Contessa

The Diamond Contessa was written by Kenneth Bulmer and published in 1983.  It's book 7 in his "Keys to the Dimensions" series.  The series consists of:

1.  The Key to Irunium (1967)
2. The Key to Venudine (1968)
3. The Wizards of Senchuria (1969)
4. The Ships of Durostorum (1970)
5. The Hunters of Jundagai (1971)
6. The Chariots of Ra (1972)
7. The Diamond Contessa (1973)

I never read the first 6, but it was no problem as far as I'm concerned.  This novel is about Harry Blakey, who is a war veteran and a porteur (a man who can teleport himself to other dimensions.) Things move along in the novel as we are guided through portals to dozens of dimensional worlds, and meet other species along the way; there is plenty of inter-dimensional perversion, as Harry seems to bed every attractive female he encounters, and even being enslaved by the Diamond Contessa doesn't stop him from knockin' boots with her...

There is a thrilling battle at the end that where our Hero, in full armored battle suit, tries to kill the charismatic and seductive Diamond Contessa.  The battle rivals any in Starship Troopers.  She, incredibly, goes mano a mano with our hero, is defeated and lives to fight another day, but alas, this is her last fictional appearance.  This book is worth reading just for the great climax at the end, it's quite a romp, and I'll pick up the others in the series when I come across them.