The element of shadows can extinguish light and fire which is said to be true due to the darkness kraata stages, however does shadow counter lightning and plasma as well? I ask because those two elements also produce light. If true that could explain why the Makuta never considered toa of those elements excluding light a threat if their shadow element can counter theirs.
I’d be careful with this; while the Element of Shadow and the kraata power of Darkness are similar, they aren’t the same thing. A Shadow Matoran doesn’t have access to the Darkness power, just like a Darkness kraata doesn’t have control over the full Element of Shadow.
However, assuming that you are asking about the Darkness ability and not Shadows, since that’s where your examples come from:
According to the Definitive Kraata & Rahkshi Guide, Darkness kraata at Levels 4 and above can “snuff out any light in the area”, before listing flame and Lightstones as example.
The key here is “any” light; no matter the light source, the Darkness power can snuff it out and create a zone of pure darkness.
So yes, the Darkness power could block out the light generated by lightning or plasma.
I was talking about the Makuta’s shadow element I only listed the kraata darkness power since it specifically mentions fire. However I guess I could have used the example of Teridax cutting off the Karzahni plant from heat using shadows.