If you earn this achievement, you'll also get A Life Facing Malice, A Life of Struggle, and A Life of Moderation.
To get this achievement and the others, you want to beat the third phase of the final boss (Armatized Heldalf) without any retries. You can retry all you want on the first two parts.
This isn't actually as hard as it seems because the harder part is the second phase. Here he won't use his mystic arte on you and if you are well geared and leveled there's nothing you can't heal. Stock up on elixirs and other healing items. Make sure to stay at the inn in Katz Corner and eat Mabo Curry as well. It also helps to have beaten as many optional battles as possible since this boosts max HP. Otherwise just make sure your attack stats are good because the key is to be able to do a lot of damage quickly. Having the Lindwer skill on characters will help greatly as well.