Mana Shield

1st-level Abjuration
Casting Time: 1 action
Range: Touch
Components: VSM($) (a sapphire worth at least 10 gp)
Duration: 8 hours

You create a ward that is powered by your mana.

Effect. While active, any time the target takes damage while you can see it, you may spend mana to reduce this damage. Each 1 mana spent reduces the damage taken by 2.

Special. If you run out of mana, this spell ends prematurely.

At Higher Levels. You can target an additional creature for each slot level above 1st.

Source: Homebrew