can essence of corruption...

Upgrade the essence type to a higher essence type

can it get +2 and more type higher? or is it like with upgrading essence tier, which will be upgraded +1 only

4 effects from corruption as far as I know,

1. Releases the mobs straight away

2. +1 to the level of contained essence (screaming > shrieking for example)

3. +1 to the tier of the contained essence (all I think of this as is purple ones > the valuable ones)

4. +1 adds an essence

Thats it really, only time i corrupt is #3 or #4 if you need the challenge, the chance of rolling gear that is any good even with a guaranteed stat is so low that it only seems worth it to try for the fruity ones.

in wiki, it does not say +1 but just a higher. which is confusing

Once you have done the challenges, it is really only worth using Remnants on Screaming Essences of Misery, Dread, Envy, or Scorn, as these are the only Essences that can turn into Horror, Hysteria, Insanity, or Delirium.