It has plenty of counters already, in banedragon and other poison mons.
A better solution would be a sleep immune monster with purify and high speed given out through the island challenge. The main reason sleep is out of control is because of sleeplocks. The main way to get rid of this is to make a monster that has a lot of potential to get out of sleeplocks. You could also give it a passive that makes it undetectable in your team. It wouldn’t show up for the enemy in the next monster slot.
Buff lightning chicken, that one is sad more than his brother.
Died easily even from water mons
You know as much as everyone else that a sleep immune high speed purifier will be a featured legendary in a festival egg. They need to make money 
Speaking of keys, how about a reduction in the time it takes for keys to regenerate?
What about adjusting the Ai buffs. Here’s my suggestion:
Allow that buffs be given to players as well as the computer. The buffs would be obtained by winning streaks. Every 5 wins will increase the stats of monsters. In addition, whenever a player or computer loses the buffs are loss and reset.
Normal — No buffs
Hard — Buff stats 25% — 5 game streak
Extremely Difficult — Buff stats 50% — 10 streak
Legendary — Buff stats 100% — 15 streak
and maybe
Impossible — Buff stats 200% —30 streak
These buffs could be shown by certain colors: Normal (Regular Font Color) / Hard Green / Extremely Difficult Blue / Legendary Red. This way we as players can combat those buffs. If a player/computer team loses the buffs will reset. Either to the nearest buff level or completely reset. The reasoning behind this comes from the UCs. When I encounter a 1 star monster KO’ing a Legendary it takes me by surprise. :huh:
If not said, with chronox there is a lot going on around him. I have not been informed about the move set for him, but his first form looks as if he preys on monsters that are about to attack. Maybe if not already has, let him also have moves such as time strike and such, to go after those monsters that have a long wait.
As well, possibly have such a move like " double poison decimater". This move would kill one monster that has a poison ability, that are “poisoners” but it also poisons a monster to deflect against it.
Poison does Not need a nerf.
Passive - Poison Immune/ Absorb
Passive - Sleep Immune/ Absorb
Active - Attack Boost (All)
Active - Lethal Killer (if killed by a lethal killer, lethal won’t effect)
double bloodfury
assisted dusk all
poison gas
assasinate
passive poison lover-regain small amount of health if poisoned.
hold ground
Robinator is already absurd. We don’t need a legendary version.
You can intentionally force losses then whenever it gets too hard to climb higher, if I understand you right.
Active
Clairvoyance (???): The next two attacks will miss, but this monster will not be to attack for that duration.
Single Out (???): Target monster will take damage next turn from any source.
Passive
Enrage: Monster does more damage each time it takes damage. (Feels like I’ve done this one before.)
Flee: There’s a 20% chance for any monster that hits this monster to flee to the end of the lineup.
Adieu!
how about replacing assassinate with desperate double
Poison eater would be better.
yes it would be
Active: climax strike. Similar to crescendo strike, only it resets when you stop using it
Duo climax blast. Does critical to 2 monsters once the user has used 5 climax strikes in a row
Life flip unlimited
Ultrablaze
Passives: hold ground
so you can spam duo blast? or does it reset?
true, I don’t really understand what he’s saying too well either, I like the idea of buffing the player, I think he means you get buffed for winning
I like the name of the skillset 
Passives:
Sleep Revenge: same as dreamy entrance, but upon death instead.
Hold Ground (only if Megabomb instead of Blood Clone Next)
Poison Immune
Moveset:
Gigalux
Accelerate Team
Sleep All (160 TU)
Blood Clone Next or 400s MegaBomb?
Very slow speed (~20%)
Should function mainly as support, to tie in to its abilities.
Meant to open the field for sleep teams more, so that you don’t have to require the specific setup of Goldtail, Stormloch and Shadowhunter (which few have all 3). Not sure if this is balanced though. Thoughts?