Never Surrender

3rd-level abjuration
Casting time: 1 reaction, which you take when you or a creature within 60 feet of you drops to 0 hit points.
Range: 60 feet
Target:
Components: V, S
Duration: Instantaneous
Classes: Bard, Cleric, Paladin, Ranger
Subclasses:

When the target is reduced to 0 hit points, it can fight looming death to stay in the fight. The target doesn’t fall unconscious but must still make death saving throws, as normal. The target doesn’t need to make a death saving throw until the end of its next turn, but it has disadvantage on that first death saving throw. In addition, massive damage required to kill the target outright must equal or exceed twice the target’s hit point maximum instead. If the target regains 1 or more hit points, this spell ends.

At Higher Levels. If you cast this spell using a spell slot of 6th level or higher, the target doesn’t have disadvantage on its first death saving throw.