...that of the Spellbinder!
The Dynamic Duo continued to face the hypnotic foe, along with his henchmen of Dipsy and Doodler, with Batman falling prey to the hypnosis of Spellbinder, until facing his foe a third time, where Batman was able to eventually break a trance of the Spellbinder on his own, ending his criminal reign of terror...
...for a time.
All this, but he still wasn't "The Master Mesmerizer of Metropolis" in the story by Martin Pasko, with art by penciller Curt Swan and inker Frank Chiaramonte...it was Superman, who unknowningly used his own power of super-hypnotism through his Kryptonian lenses to make people think Clark Kent and Superman looked differently!
Back To The Bat
Batman took out Spellbinder first, and used his identity to go and defeat the others, bringing Spellbinder's Silver Age career to an end.
A Few Friends
The Bouncer first appeared in Detective Comics #347 (January, 1966 by Gardner Fox, Carmine Infantino and Joe Giella), and was a man in a special suit of "elastalloy" which allowed him to bounce off any object...at least until he met Batman's fist!
...but, in more recent times, the Monarch of Menace was disappointed in his son (who then went out to be beaten by Robin, while disguised as his father using his many gimmicks hidden in his crown and scepter, prompting much angst in Batman). Batman was able to beat the Monarch of Menace on his return (all under this awesome Joe Kubert cover!).
The Bouncer came back, along with Cluemaster and Spellbinder, as mentioned above.
An Ending Starting Again
Hellgrammite, then in Birds of Prey: Batgirl #1 (February, 1998), for a trip to Apokolips in Birds of Prey #12 to #14 (December, 1999 to February, 2000), being part of Circe's female army in Wonder Woman #174 in November, 2001, being one of the many affected by Joker's gas during the Joker's Last Laugh (and in Birds of Prey #36 of December, 2001), before her last appearance being shot down along side the Trigger Twins in Infinite Crisis #7 (June, 2006), though that ending, like Delbert's end, could have been an illusion....