Ooh, I'm an expert on these people because they're attracted to me. Kinda ticks me off but I can help here.
Alex/Tas/Mental_Tails is the guy who messaged you. He's not blazefire, but they're friends. I have both on MSN, and their login times are severely different. There may be a reason he's mental_tails. Him and blaze argue, and apparently blaze knows tas's passwords and impersonates him. They make different grammar mistakes. Tas is worse.
Redsonic is more of a deception/impersonater. Tas is way too stupid to impersonate. Redsonic is friendly with Blaze apparently. I have dealt with Redsonic impersonating Streak, Tas, Blaze, and a girl. Him and Blaze were also browsing my personal files on Smash Bros Stadium, prompting me to make it harder to browse.
My theory? Blaze or Red found the area the new SCD was in, showed each other, and showed tas. Tas is stupid enough to tell someone who matters. But yeah, there's my theory. Hope it helps.