Argentum Insult

You magically insult the triggering creature, turning its success into momentary uncertainty for them and encouragement for another. The triggering creature must reroll the d20 and use the lower roll. A creature can be caused to reroll the d20 by any casting of this spell once per round.

You can then choose a different creature you can see within range (you can choose yourself). The chosen creature has advantage on the next attack roll, ability check, or saving throw it makes within 1 minute. A creature can be empowered by only one use of this spell at a time.

If you caused a 20 on the d20 to be rerolled, the spell's magic is consumed by turning overwhelming success into a potential failure, and as such, no creature can gain advantage from this spell and that portion of it fizzles. If you caused a roll to be rerolled that had either advantage or disadvantage, said advantage or advantage are maintained for the reroll.

Note: This is a feeble attempt at still having Silvery Barbs...well, exist in the game, while reigning in its capabilities.

TLDR on changes: you can't cast the spell on a saving throw you caused yourself, a creature can be affected by the spell once per round, its range is halved to 30 feet rather than 60, if used on a roll with advantage or disadvantage they maintain said effect on the reroll, and if used on a natural 20, the advantage portion of the spell does not activate. Is it still too strong? Probably, but at least not oppresively so.