[SirAlvarex]

I've only tried to solo light blue casters without fear, but for that I just use my resist songs. Their spells will almost never land.

You might want to just do chain mezing, since it interrupts spell casting. Most spells seem to take longer than 3 seconds to cast, so you might be able to lock casters down.

Charm is...risky. I haven't used it solo in dungeons since you'll get beat on by two mobs at once typically. If you are able to do it reliably, then that sounds like a great option!

Something I've never tried before is Mezing + Mana Drain. Since mana drain does no damage, maybe it doesn't break mez? If so, that might end up working if the mob doesn't have uber mana pool.