Uno was a Vanguard, a supreme defensive class that boasted impeccable defensive power. He alone could fill in the role of 20 normal tank classes, yet due to his character, he loved to engage enemies through a mixture of aggressive defending and aggro-focusing.
And that's what had made the 'Godless Paladin' special in the previous timeline. The majority of tank class fighters had developed the mentality that their only job was to receive hits and let the others handle the damage output. Uno had drawn the line and had opened a new field of play by tanking while also focusing on dealing damage with status effects, mostly stuns thanks to the hammer.
He had perfected his style to a degree that it had been recognized as the 'proper' way of playing a tank class, so it was natural it would excel even greater in this timeline after Eva had drilled the foundations into him and had guided him into the proper direction.