Ok, so how powerful is this living saint you may ask? well, stupidly powerful the most outstanding stats are her WS, BS and I of 7, not to mention 5 attacks base and being the only Sister of Battle with a 2+ Armour save. She is also Jump Infantry, making her an amazing addition to a Seraphim Squad. Her wargear is unbelievably good, she wears the Armour of Saint Katherine which gives her her 2+ save and a 4+ Invul. save and her weapon of choice is the Ardent Blade, a Power Sword that alway wounds on a 4+ unless she can do better, this makes up for her Strength of 3, the blade can also be fired as a Heavy Flamer.
Now for the best part, Saint Celestine's rule Miraculous Intervention, every time she dies, place a counter where she died then at the start of every one of your subsequent player turns, on a 4+ she comes back to life with D3 wounds! She is almost unstoppable though her Toughness of 3 make her quite easy to kill and she doesn't have Eternal Warrior. But how many points is she? surely this undying saint is around the same price line as Mephiston or Abbadon, nope, Saint Celestine is only 115 points which is just stupid cheap.
This is the HQ you want in order to avoid giving the enemy Slay the Warlord. Saint Celestine is the a hero, more aggressive than supportive, although she does boost Seraphim squads immensely. By far my favourite character in the Sisters of Battle codex.