Here's an explanation, it's also deady in hell if you use skills that put into hit recovery
edit more info since you died to the frost one :
When Unique is Cold and Fire Enchanted, two novae and two explosions will be released upon death, although the second of each will be invisible. [6] [7] However, since coldunique missiles have 3 frame next delay, only one will apply its cold damage and length. [8]
When a Unique is Cold and Lightning Enchanted, an invisible nova will be released whenever it is put into hit recovery. [9] [10]
Cold Enchanted Scarab Demon will release an invisible nova whenever it is put into hit recovery. [11] [12]
Cold and Lightning Enchanted Scarab Demon will release two invisible novae whenever it is put into hit recovery. [13] [14] However, only one will apply its cold damage and length.
https://www.theamazonbasin.com/wiki/index.php/Cold_Enchantedooh man RIP. Great character :(