I thought this was really nice!
I have to mildly (but respectfully, I hope!!) disagree with a couple of minor thoughts on upgrades.
These bits of damage happen after the main spell effect, which includes damage to all enemy troops. As such, any Barriers will have already been expended against this bigger hit, unless the Troops were Submerged (in which case only Rending has a chance to have an effect).
The main exception to this would be triggering an enemy’s Savior talent by killing an enemy Troop with the initial ‘damage all’ – this seems pretty niche, though. The upgrades can also be detrimental against an Orbweaver hero or Orcs.
On the whole, therefore, I generally find the damage to be either meaningless, unreliable, or occasionally/situationally/rarely useful against Troops with ~1-3 Health left – so not really that nice or good (my opinion/take).
I totally agree, and realistically think this reasoning applies to a lot of the other upgrades as well, making them less useful.
But yeah, I guess Leeching can be useful if you gain 2 mana, Vampiric is fine because you gain 3 Life and could kill an enemy with ≤3 Health, allowing you to use the Skull hits on the next enemy (also an argument somewhat in favour of Striking), and so on.
I do agree with your thoughts on Glaive’s Tangling, but also sometimes kind of wish it Entangled the second enemy (either instead or as well), though .
I’ve typically/historically always agreed with this – after all, if making Doomskulls, why not have more?
Lately, though, I’ve considered a couple of situations where it’s actually detrimental ():
When it joins two disparate skull groups, to subsequently deal less damage
If you were to cast it when there would be no available Skull matches afterwards, and considered ‘safe’, but creating a Doomskull opens up a Skull match for the enemy.
At the end of the day, I think ‘Create a Gem’ upgrades simply don’t belong on Weapons that Convert Gems, since Converting Gems is all about predictability, consistency, precision, etc.
Loving your breakdowns of various game elements, tbh!!!