What do you want to use it for? I have both a SK and an MCII (both awesome) but I use them differently (tele with one and les paul with the other) so I'll never sell either of them.
The MCII definitely lacks in gain compared to my SK and the low end can be wildly different (which is where I think MTL might be more similar in). It's definitely more vintage feeling, but if you get a newer one with the Pull Shift knob then it helps tighten the low end up (though still needs a boost for higher gain). Boosting an MCII can help but still don't think it gets that close to a SK for higher gain stuff. For mid/lower gain stuff I think they're both perfectly capable and their voicing isn't too different (SK is probably closer to a Plexi while MCII is closer to a Silver Jubilee).
If I had to guess I'd say the MTL might be most similar to a SK, but never played one to confirm. Both seem to have big low end with a Marshall flavor highs. The MTL is essentially just an MCII with an extra gain stage up front (and then maybe different power tubes depending if you got a hybrid or not).
Hell Raiser...no idea man. Every clip I hear online this thing lacks low end but also might just be the more modern metal style guys are going for which isn't me. Also haven't heard anything but crazy high gain.
I might be alone in this opinion, but as awesome as Wizards are they aren't head and shoulders above some guys these days (like Monomyth, GZA, etc).