Vesper totally have two attacking methods, one is to send out missiles to where you stand, so we need to run all around when he attacks, the amount of missiles are from 2-5.
The second way he attacks is by attacking all around, but this one will only come when his HP is below 40%.
So just be patient and careful, take your time and we can go through Vesper, but since it is only the second boss, I think the following ones will be harder and harder.
After finish all the stuffs in this village, we need to go further to find some secrets of the Pray Spring, so keep going.
It seems that the water of Pray Spring is poisoned, and the people will become undead if keep drinking it. But right now I seem to have difficulty to enter the west Ponteras. I have transfered to Crusader, and finished the quest from the Church, see if this can help me to get to the west ponteras.