Ultimatum chimera boss cry

GGG, can you change behaviour of that thing? I have build with decent survivability but low and consistent damage output. Fight with this boss is torture. 15 mins of chasing boss all over 3 stories arena. 1/3 of the time its fly to you (in this time it's invincible), making a aoe slam, FLIES UP AND BREATHES FIRE (in this time it's invincible) and flies away to some distant place in the arena (in this time it's invincible). It's not hard, but very frustrating and tiring