User blog comment:Mich, Michele & Kuhla/Future Units Preview/@comment-204.169.28.98-20151119153734/@comment-26336535-20151121174812

Actually, Anon, Cardes wasn't even released when Azael was released, so no, "even back then" Cardes wouldn't have been a better leader since he didn't even exist. Also, a lot of 6* units didn't provide buffs on SBB in his era. He was used more for damage. Note that I was talking about when he was first released, as in when every 6* had something around his stats, and he was one of the damage dealers since he hit with both Light and Dark elements (also a first I think), and gives attack buffs to two elements and elemental damage reduction buffs against two elements in one LS.

TL;DR: Check your facts, units that were non existent can't outclass a unit during its time. Nothing could do what Azael could do when he was first released. Most of the 6* that provided buffs on SBB also inflicted lower damage.