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. When you cast this spell using a spell slot of 2nd level or higher, you can target an additional creature for each spell slot above 1st.

Source: Homebrew