This likely has to do with the way the game is coded.
Rain of Fire, Pandemonium, Thunderstorm, Flooding, Plague, etc. all select appropriate targets and apply their effects one at a time instead of all at once. Because of the way that the 'targeting' works, Immaterial creatures are immune to mass-CC.
Wrong.
Those spells do not affect immaterial targets because when the game loops through creatures to deal damage/poison them, it specifically makes sure the creature is not immaterial. In other words, Zanzarino wanted them to not affect immaterial creatures. If he wanted to make, for example, Thunderstorm affect immaterial creatures, he could (though that would be bad for consistency).
Based on this information, is it possible to code AoE or Targeting spells that ignore Immaterial?
As I implied, that's what the code would normally do had Zanz not specifically made those spells not affect immaterial creatures (for AoE). As for targeting spells ... it is possible but suboptimal and makes for bad game/card design.
One key thing here is the "controversy" of affecting Immaterial creatures. Before the introduction of SoW, it seemed to me that the targeting, much less affecting, Immaterial creatures was regarded as Taboo, save for the passive effects of several shields. But even with the addition of SoW to the card pool, there seems to be some hesitance as to negatively affecting Immaterial creatures.
The issue here that I see is that if Immaterial targeting would be implemented, how would the cost be balanced? Would it cost more, since it has to put up with the minority of Immaterial [Comparing the abundance of CC to lack of PC] and the extra cost of using a Quint on a creature? Or would it have to cost less, since the range of affected creatures is much smaller than the standard CC, assuming the range is limited to Immaterial?
Considering Mass CC, any inclusion of an idea that would affect Immaterial would reduce the value of Immaterial, lowering the costs of creatures that have it and the casting cost of Quint.
In terms of targeting CC, again, SoW has made it clear that it is possible, but, as stated above, there is a question as to how it is balanced. I would say costs would be increased by 1
and, as it being allowed and maybe accepted grows, Quint will need a buff to compensate, probably by dropping to 3|2
cost. But that is only under the assumption that more Immaterial CC ideas come to light.
