So Riolu in my Pokemon is Ice type and Lucario is Ice/Fighting. The ability I decided for them is Justified with Mega Launcher as its hidden ability.
Guess I'll take this chance to talk about mine.
Snow Riolu in my game have the same sort of setup as regular Riolu. The difference is purely cosmetic. When evolved like normal, they evolve into normal Snow Lucario, which are also a purely cosmetic change versus regular Lucario. But when Snow Riolu evolve by having high friendship and leveling them near the Frost Boulder, it'll evolve into a different kind of Snow Lucario, which have a few new toys.
Name: Lucario
Form: Ice Embrace
Type: Fighting/Ice
Ability: Arctic Aura: Reduces damage from supereffective attacks and powers up not very effective moves
Base Stats: 75/100/75/100/75/100
Signature Attack:
Aura Beam: Ice-Type version of Aura Sphere.
More rounded-up version of regular Lucario. Has an amazing double Ability (Filter/Tinted lens) due to its frailness and semi weak offensive stats. It also has access to a new Ice-Type move a few other Ice Pokémon can learn called Chill Dance, which raises Sp. Attack and Speed.
The form Ice Embrace is share by three other Pokémon- Arcanine, Ampharos, and Grumpig.