Reading one value from an array in reverse

[DreamingInsanity]

Take this array: [[100, 200, 0], [100, 300, 1], [100, 400, 2]]
It can be split into three things: [position1, position2, message]
I can reverse the main array using the [::-1], but when I read from it, and use that data, the result is the same.
Is there a way I can read just the last value from my array in reverse.
So, if I print the current array it is:

Output:
[100, 200, 0]
[100, 300, 1]
[100, 400, 2]

but when I reverse just the last value, it will be:

Output:
[100, 200, 3]
[100, 300, 2]
[100, 400, 1]

How can I achieve this?

Thanks,
Dream