Whenever you would deal damage, you instead deal that amount of wither. This wither has no damage types, but is otherwise treated as it would be prior to affecting its targets. So, Triumphant Damage Boost would boost it, but Improved Brace would not deboost it.
Whenever you would deal damage, you instead deal that amount of wither. This wither has no damage types, but is otherwise treated as it would be prior to affecting its targets. So, Triumphant Damage Boost would boost it, but Improved Brace would not deboost it.