Master Focus

Supreme focus allows you to maintain concentration on two different spells. The first turn that you maintain concentration on two spells, make a DC 10 check with your spellcasting ability. Every turn after the first, the DC increases by 2.

After taking damage, make a constitution saving throw to maintain concentration with the DC being 10, half the damage taken, or the current DC of Master Focus; Whichever is highest. On a success you maintain concentration on both spells. On a fail you lose concentration on the first spell cast.