In my opinion, they should already exist, they sound quite nice.
If I can spin this a different direction, maybe there should be a global 10% Augment spell: just add it to whatever card you want, and it enhances the effect of that card.
Examples: Add to an attack card, +10% damage. Add to a shield, +10% resist. Add to a trap, +10% damage. Add to a weakness, -10% damage. Add to a bubble spell, +10% to all school attacks (Wyldfire, Balefrost, Darkwind, Time of Legend), or +10% to all heals (Sanctuary), or -10% to all heals (Doom & Gloom), or +10% power pip chance (Power Play).
