Re: the dead zones ask -

Caused by the presence of what were originally high-magic artefacts that have either degraded over centuries or been destroyed by the Transcendence, either way their magic leached into the surrounding area. These zones are so saturated with the artefact’s specific magic that there is no natural background magic. At all.

Magical creatures cannot survive here, most cannot even cross the boundary. Magic does not work unless it uses the specific saturating magic type - and as most magic uses generalised power this is extremely rare (ie most magic uses the full spectrum or a colour section, this area only allows this particular hexadecimal colour. Even a fire magic user in a fire artefact zone is unlikely to match the exact frequency and even then will be severely reduced in power having to use only #FFA500 instead of all orange power).

Extremely powerful entities rebound right off the boundary as their innate magic reacts to the null zone border by trying to compensate for the missing magical frequencies. The backlash is generally quite spectacular.

Alcor is able to pass through them unharmed by reigning his power down and containing it under a human, magic-free shell. (Yay corporeal bodies!)

He can even use his powers once he masters the fine tuning required to match the area frequency with little power loss, since he has almost infinite power reserves to call on rather than using ambient magic.