Eternal chains

as soon as the caster utters the words "eternal chains" the sky will darken and burning white chains wrap around the target and if that target is under 25% of their max health that target is cut in half almost as if the chains are a knife moving through butter but if the target is over 25% max health then the target is now bound in place and can't move until the caster releases them or if the chains are hit with the weapon "blood blades" along with being bound in place the target gets damaged over time for 2% their max health and if the target is put under 25% of their max health this way then the target explodes but also heals the caster and whom ever they choose