Help on spell shelter

Current upkeeper: Zarch
Casting time    : 8
Spell cost      : 500
Spell type      : generic
Spell words     : Summon ex Liberia
Affecting stats : Wis, Lvl
Affecting skills: Arcane power, Mastery of shielding
This spell will create a flashing  barrier of energy that will prevent  anyone
entering the space  occupied by this  field.  This protection  is not  without
limitations  though and some inviduals  might be able to push  themself trough
the  barrier.  Certain  stats and  skills will  help to  fortify the  barrier,
making it less  vulnerable for such  breaches. Some  areas   concentrated with
magical forces might prevent the spell working at all.

Sharpen blade < List > Shield of elements