you would be inside of a cabin, in a small town on a mountain taking a break as you recovered from the long journey up there with your pokemon as you were inside you looked out the window to see your Lucario sitting with his legs crossed on a stump as the snow would fall around him he would have his eyes closed as he continues to meditate not letting even the snow bother him.
When you were younger you would of told him to get inside because you didn't want him to make himself sick or or I'll while being in such harsh conditions but as you grew older you both formed an even stronger bond of trust, and you know he's completely fine outside there without you having to watch over him from time to time, of course if he does start to feel cold he usually comes in and will warm up by the fire or by having some hot chocolate.
Of course your Lucario could actually tell you something is wrong with him from since he was a Riolu you don't know how he knows to speak English but you're happy you actually can have a conversation with him even if sometimes they're brief conversations or very long ones. Of course sometimes you'd have tired yourself out by making sure he doesn't tire himself out and you'd fall asleep were you stood of course you would always wake up in your own bed, at first you used to think the day care couple (the people who took you in after your parents went missing or passed on.) Were the ones who picked you up and put you to bed, but no it was your Lucario you'd find that out one night of course when you saw him leaving your room after you got placed into bed, before that moment you didn't think he actually cared about you being his trainer or him being your partner but that moment let you know he truly cares about you.
You would then walk away from the window before sitting down on the couch with your cup of hot chocolate and turn the TV on to watch wherever you planned on watching chuckling a little bit as you knew you couldn't convince Jack to come inside.
As the snow would continue to fall down to the ground you would enjoy the warmth of the roaring fire and hot chocolate while also occasionally checking on Jack out there to make sure he is still alright. Your Lucario is special as his fur is mostly black with his fur on his ears and paws being red. Although another thing you had noticed while on your journey is that Jack despises and outright hates Team Rocket even if there's a type advantage against him he'll still have you choose him to battle any team rocket members you face. Of course you tried asking about it but he never says anything and he keeps that information to himself.
The fire would soon start to get colder as you would toss a few more logs onto the fire and then you went into the kitchen to make yourself some more hot chocolate. Although as you did this you were a little bit more worried with how much snow was piling up the ground as you decided even though he would probably refuse to come back in you wanted him to be inside where it's safe.
You'd set your cup on the counter before heading out the front door and walking over to the rock he was meditating on, and as you got closer you could see he knew you were there as his tail would move a little bit while he kept his eyes closed but he would relax a little bit more.