Dukhogon's Cognitive Expansion

Your mind enters a state of pure focus, allowing you to perform the complex mental exercises necessary to maintain multiple magical effects. For the duration, you can maintain concentration on two spells at once. One of the spells must be of spell level 2 or lower, and you cannot maintain concentration on multiple instances of the same spell.

If you cast a third spell that requires concentration, you choose which of the two spells currently concentrated on to replace. If you fail a Constitution saving throw to maintain concentration, you lose concentration on all spells at once. If you are maintaining concentration on multiple spells when this spell's duration ends, choose one spell to continue to maintain and the rest end.

At higher levels: when you cast this spell using a spell slot of 5th or 6th level, the requirement changes to one of your spells must be of spell level 3 or lower. When you cast this spell using a spell slot of 7th or 8th level, the duration increases to 8 hours, and the requirement changes to one of your spells must be of spell level 4 or lower. When you cast this spell using a spell slot of 9th level, the duration increases to 8 hours, you have Advantage on all Constitution saving throws to maintain concentration for the duration, there is no requirement on spell levels, and you can maintain concentration on three separate spells (you still cannot maintain concentration on multiple instances of the same spell).