+break or +power on enchanters skills

what is better enchant path on isses skills?
all+break or all +power
and how does that break works? (does it add ignoring power of pdef (like cripling -40% so with break -45%) or its like power just that moment it ignores pdef (so make more dmg from that skill like with +power), does effect of that -5% ignoring pdef from break remains while cripling is on (those 20s all making more dmg to that target)