Lucario:
It controls waves known as auras, which are powerful enough to pulverize huge rocks. It uses these waves to take down its prey.
Lucario reads its opponent’s feelings with its aura waves. It finds out things it would rather not know, so it gets stressed out easily.
It concentrates its mental energy and fires off mysterious waves called auras, which can crush boulders of large size to dust.
They can detect the species of a living being— and its emotions—from over half a mile away. They control auras and hunt their prey in packs.
Not only does it perceive auras, but it has also gained the power to control them. It employs them in battle.
By reading the auras of all things, it can tell how others are feeling from over half a mile away.
By catching the aura emanating from others, it can read their thoughts and movements.
It’s said that no foe can remain invisible to LUCARIO, since it can detect auras. Even foes it could not otherwise see.
It has the ability to sense the auras of all things. It understands human speech.
Lucario controls auras, and uses them to attack.
Source
Riolu:
The aura that emanates from its body intensifies to alert others if it is afraid or sad.
They communicate with one another using their auras. They are able to run all through the night.
It uses the shapes of auras, which change according to emotion, to communicate with others.
It can discern the physical and emotional states of people, Pokémon, and other natural things from the shape of their aura waves.
It knows how people and Pokémon feel by looking at their auras. It doesn’t approach dangerous opponents.
It uses waves called auras to communicate with others of its kind. It doesn’t make any noise during this time, so its enemies can’t detect it.
It can use waves called auras to gauge how others are feeling. These same waves can also tell this Pokémon about the state of the environment.
Riolu uses auras to communicate, and has auras emanating from it.
Source
TLDR: Lucario controls auras, and uses them to attack, and Riolu uses auras to communicate, and has auras emanating from it.
