Asalorium's Arcanum Flow

For the duration of this spell you may concentrate on two spells so long as their combined levels are equal to 5 or less. While concentrating on two spells you must make a concentration check at the end of each turn additionally anytime you take damage the resulting concentration checks are made with disadvantage. Any failed concentration check causes both spells to end.

When cast using a higher spell slot for every 2 levels the combined spell level can be 1 higher. Using a 7th level the combined levels can be up to 6, and 9th level the combined levels can be up to 7.