PHL and DKO work kinda like Naval Commander where their skills get more powerful the more party members you have. This means you actually have to use the party system to use them to their full potential.
PHL used to be bugged where you could just spam the debuff skill and it would keep stacking until the enemy actually heals you instead of damaging you but I heard its been fixed now.
Legion Paladin is just a shitty version of the Paladin.
I say shitty since some of the skills backstabs you more than it helps.