Xephy's Arcane Escalation

As a reaction, you may add your power to a spell being cast within 30-feet of you. You must make an Intelligence saving throw against the spell save DC of the caster of the targeted spell. On a success the target spell is cast at a higher level by one spell level. On a failure you immediately take Psychic damage equal to 2d6 plus your spellcasting ability modifier. If this spell is subjected to a Counterspell, you automatically fail the save and take damage.

So Far Beneath Me. Spells that are lower than one spell slot level than this spell is cast at may be automatically elevated by one level without making the saving throw. Any higher than one level still requires the Intelligence saving throw versus the target spell's save DC. For example: casting this spell at a 5th level may automatically elevate a 2nd level spell being cast to 3rd level, but you are required to succeed on the save if you aim to elevate the target spell from 2nd level to 4th or even higher to 5th.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you may elevate the spell an additional spell level on a successful save per spell slot level used above 2nd. Damage incurred is also increased by 1d6 on a failed save per spell slot level used above 2nd. According to Cosmic Law, no spells cast may be raised higher than the 9th level.