Cherry Sage and Paederia in particular really benefit from having life steal on their special skill since they have damage reduction (-10% pest attack power) and attack power boosts (+30% for herself and two allies against bosses with Cherry Sage, +10% attack power with no strings attached for the entire party with Paederia). Get -60% pest attack power from the other four squad spots and either of those two Knights can last a LONG time against all but the strongest of boss pests.