Put Saviour's Sacrifice On More Item

Hate to break it to you, but neither of them will do fine:

• Heroism is a Rare - it cannot have Major IDs.
• Nether's Scar having negative Health Regen is more or less rendered moot by its high Health Regen% ID with a sufficiently decent roll. I'm not even sure if it would make a good candidate either.

If you want to put it on an item, put it on a Fabled armor which is gimped in some way due to how powerful the ID is for a skilled player. Second Wind could use some buffs in that regard, even though it is balanced around having the highest Health Bonus sum of any leggings in the game.

Putting it on a Legendary makes it way too accessible (even though Fableds are also easily accessible due to the limited number of items in the pool still).