Garuda Aiacos is the S unit for January on the Global server. It is a support, DPS character with high damage. The new Aiacos basically serves to give an ally an extra accelerated turn, reducing their energy consumption to 0 and dealing damage at the same time. But Aiacos played with Aioros Divine Cloth or Defteros can do this more than once, in a kind of loop combo. Not an infinite number of times, though. Of course, this comes at a cost: we subtract HP from allies, so it's a weapon that carries a small risk. Aiacos has buffs to increase his survivability and is generally a character with good resistance..
It wouldn't be a bad idea to see him in more traditional lineups either. Is he a Defteros 2.0? A little bit, yes, he's not as fast and doesn't do as much damage in the long run, but reducing consumption to 0 and having his own survival mechanics can give him a place in the Meta.