From my Point of view Venthyr seem the worse Ability for Holy pal.
There is really neat combo u can do with all other. While Venthyr doesnt really have any Leg to make a good combo Gameplay. Night Fea Either but with the Auras that give 50% cooldown reduction on self. Its quite strong Might be harder to play but Might help u stay in Crusader state longer. Which can be a good combo for melee healer build.
Necro Lord has good combo with Martyr if u use Soulbind And the Leg that boost from Dawn or that make it affect the target of your beacon.