Where do you see stat costs? Are you sure 3 def is only 6 nora? Stat information would make a firking happy Poxxer. The practical advantages of tough over defense: Strike ignores def, Tough remains unscathed - this applies to any damage ability that ignores def*; Sunder/Cripple can't touch Tough; Tough reduces AoE champion damage, AKA Auras(including Deafening), Cones, Pings, Bolt Abilities, Novas, Poison Cloud, and several others; Tough reduces Spell damage*. *And as a side note for Fist of Bastion, that means that with tough 3, resilient and IS FF bonus you need to deal at least 13 spell damage to have him take 4 damage. And with 2 base def and the same upgrades it means that a champion needs to have at least 10 damage to deal a minimum of 4 damage to Fist, remember I'm not adding any buffs. As for the advantages of defense over Tough: Loss of Life attacks ignore tough( and any damage mitigation abilities), but defense still works against them.