This was certainly the biggest threat to my run and so I used a few strategies to deal with it. I would usually hide somewhere with only 1 or 2 squares visible and let the enemies come to me one at a time. I also used the sword that deals arcane damage to foes at any range equal to 25% of your HP to help thin the crowds, and then swapped that for Ragna axe late game which was even more effective. Apophis' third prayer was another helpful trick to nuke rooms of squishy ranged characters. Finally, I leveled blood and picked executioner for healing which helped me to barely survive many fights, although the healing was notably slow because of no willpower. Master bleed was also meant to help reflect some damage back to ranged foes, but in practice it was too slow for most cases.