Flamme's Hindsight:

If successful, reroll a failed check involving a d20. If the original roll was a natural one, double the initial cost. If cast by nation magic, suffer -2 temporary karma for every 1 the caster misses the DC, in either directions. If cast by character magic, caster suffers a 10% chance to reduce their magic attribute for every 1 the caster misses the DC, in either directions. If the above downsides are mitigated in any sense, increase the base cost and complexity by 2. A single Mech RP can only gain the benefits of a hindsight spell once.