So I've been playing a while and after reading WoL Guy Gardner's carry trait, I came up with this question.

Do you -2 from your speed for each character carried, or -2 regardless of how many characters you carry?

I have subtracting two for every character carried, like when I use SoG Void, have I been hurting myself without my opponent knowing this whole time?

Its just -2 no matter how many you carry.

Alright, thank you, I understand now. I was confused because let's say Guy Gardner did carry 8 characters. That would be MINUS 18 to his speed. that caught my attention

Capped by the rule of 3, of course (if that were the case).