So, to summarize my understanding:
Maxwell's Demon kills both rays and also dies. Upgraded Maxwell kills both rays and becomes 3|3 or 3|2.
Fallen Elf mutates the rays and dies. Fallen Druid improves both rays and dies to the Whip Ray.
Purple Nymphs antimatters and dies to both.
Virus and Retrovirus behave normally.
Grey/Death Nymph perform Aflatoxin on rays and become 0|2 or 0|1.
Otyugh/Elite Otyugh at 1|6 will kill either ray then become 2|5 or 2|4.
Auburn Nymph performs Basilisk Blood and becomes 0|1 or dies. Earth Nymph becomes 0|3 or 0|2.
Your own (or enemy) Green/Life Nymph could perform Adrenaline and survive.
Red/Fire Nymph could perform Rage to kill the rays and survive the process.
Arctic Squid/Octopus would freeze/congeal the ray and die.
Toadfish could infect the rays and become 5|2 or 5|1.
Mind Flayer could unsuccessfully lobotomize the rays and die. Ulitharid unsuccessfully lobotomizes and becomes 3|2 or 3|1.
Guardian/Archangels heal the rays but take damage in the process.
White/Light Nymph could use Luciferin since this ability is passive. And if there are several on the board could die in the process.
Flying Owl/Eagle's Eye will kill the rays in 2 shots but end up with 3 or 1 health.
Anubese immortalize rays and become 5|6 or 5|5.
Flying Eternities rewind rays and become 4|6 or 4|5.
Scarab at 2|6 would kill rays and become 3|5 or 3|4. Elite Scarab the same but with 4 attack after.
Parasite/Bloodsucker would infect rays and die.
Black Nymph would perform Liquid Shadow and become 3|3 or 3|2. Dark Nymph the same but with 5 attack.
Flying Lobotomizer/Electrocutor could attempt a lobotomy and become 5|2 or 5|1.
Turquoise/Aether Nymph would immortalize rays and die.
Any attacking creature due to Gravity Pull/Force would suffer damage and possibly die.
I think definition wise, an active ability would not work frozen/delayed, but a passive will?EDIT: Testing in trainer. Devourer(Pest passive) does not work frozen/delayed, but Swarm(Scarab passive) and Poisonous(Chrysaora passive) do work when frozen/delayed. So it looks like it is your choice how Whip would work.
It is an interesting concept and works against all elements, but it seems to target underused or underpowered creatures, mainly nymphs. And that would make it underused itself.