The video and bug report posted by DracoL1ch are sufficiently explained by expected behaviour. What you’ve described may warrant its own bug report, but seems unrelated to this and would need screenshots / video.
I just tested Trick and Treat myself on a Blessed enemy, and can confirm that it had Cursed in its list of effects, which doesn’t make sense – so yeah, that might need further investigation. I don’t think anyone’s really inspected Trick and Treat that closely.
In the above video, DracoL1ch’s Essence of Evil is upgraded to +10 with the ‘Damned’ affix. We can see that after casting EoE, the enemy Ancient Golem is left with Curse and (then shortly after, the) Disease status effects.
- The Curse from EoE’s spell effect was negated by Bless:
https://gemsofwar.zendesk.com/hc/en-us/articles/115000335886-All-status-effects-and-immunity-Traits- - All other status effects from EoE’s spell were resisted by Impervious:
- The ‘Damned’ affix then applied Curse after the spell effects had finished being applied (purple swirly):
Note, just purple bars (Curse), no Disease yet:
- Then, Disease is applied by the Plaguebearer Talent from the Chaos tree, as DracoL1ch is using the Archmagus class:
I definitely appreciate Bramble’s earnestness in diligence in marking this Investigating, based on concerns raised and Stratelier’s comment, but the video in question doesn’t betray any expected mechanics.
There have, however, been various requests to update tooltips and trait descriptions to make this clearer in-game, rather than having to navigate the game guides to work it out (and there wouldn’t be an easy link to the status effects page from the battle screen when selecting a troop).
This would potentially have cleared any confusion before the bug report was made.
I’m very much in favour of the following, for Impervious:
The confusion for the Blessed tooltip comes from using the term ‘Cleansed’ (which typically removes Cursed AND all other status effects). It and Cursed potentially need a second tooltip to say what’s in the Help Centre snip from above, or something like: