User blog:Andras Lucifer/Karna Masta- Am I doing something wrong?

After 50% HP on the 2nd Phase, for the first few turns he is standable, I don't really start losing units but by the time he is around 30% HP I start getting completely destroyed, my units start getting one shot and I don't know why

My Squad is

Omni Sirius Lead

Omni Krantz

Omni Selena

Allanon

Gazia

What is it that I am doing wrong? I made it to the 3rd phase one time and I only had 3 units alive so I couldnt get the 3 UBBs in time

PLEASE HELP

My Omni Units besides the ones in squad are- Silas, Vern, Kalon, Avant, Vargas, Izuna, Azurai, Elza, Iori Yagami. Altro

My 7 stars are quite alot but the most potentially useful are Rouche, Andaria, Aurelia, Grahdens, Elimo, Ark, Dolk. Lafiel

Any Strategies, tips on BB useage (yes I am aware of the battle's BB useage rule), units I should get please help