Lesser Ward of Shielding

This is yellow when learned at 340, green at 345, and gray at 350.

Heres how it works:

You need to have your shield equipped, and then use the rune. The rune doesn't actually enchant the shield, unlike the rune of warding.

Instead you get a buff that will absorb the first 1000 damage you receive, kind of like PW:S

If you unequip the shield, the buff is destroyed

The fact that this requires a shield, doesn't recharge, and has a cast time to apply, means this would only be of value to tanks preparing to pull a boss and wanted as much initial life as possible

Definitely a recommended way to level BS from 340 to 350, especially if your Guild has the "Working Overtime" perk, gained at guild level 14. With that perk, I just hit 350 from 340 with 14 adamantite bars.