GREAT THREAD Jim... I thought the spike on the hilt was for a number of possibilities !!
1. Protecting the slice by an opponent to the sword hand wrist. In the Khanda with the right angle turn that could disarm the opponent>
2. Possibly used to finish an opponent by using a two handed grip using the spike in its straight form for the spare hand...
3. As a striking weapon to the opponents face neck or eyes again in the straight form.
4. As a counterweight to the blade simply adding weight at the pommel.
Wikepedia notes many Gods wielding Khanda and in Indian Martial Arts particularly the form called Gatka the Khanda is often seen.
HERE below is a goddess from the 7th C. using a Khanda form. By Pavan Srinath -
http://waxingnonsensical.blogspot.com, CC BY-SA 3.0,
https://en.wikipedia.org/w/index.php?curid=16635629
Such importance is given in the indian martial arts systems that I should mention Gatka, the Sikh Martial Art form Please see
https://www.sikhiwiki.org/index.php/Gatka
Ibrahiim al Balooshi.