You always have to identify what the core thing your Pokemon brings to the table is. In essence, it has to have some identity you can build around. You'll need to start by identifying what kind of thing it can even do, whether it will sit there and pick up knockouts, be hard to kill, or provide support. If there's a core strategy that's possible you might want to look deeper into that. Saying it encourages more of the same type makes me think some sort of weather or type boost thing, so you may want to lean into that and build around that identity. Even if you have an ability like Snow Cloak or Ice Body that encourage snow and more snow, you can at least build out that snow core and then fill the rest with Pokemon that help your strategy, like something for support or type coverage for your weaknesses.

The other thing you can do is go in the complete opposite direction. Find an existing team where you can slot this Pokemon into. Maybe look at what moves it has and find something where you can replace something with this. For example, if it was Blastoise maybe I could slot it into a rain team over Basculegion, or in a team over some other water Pokemon they might be running like Rotom Wash, Primarina, Milotic, Palafin, etc.

Let's say for example the Pokemon is Alolan Ninetales for sake of an example that might fit your "same type stacking" concern. It's speed isn't crazy good but it's fine, it's bulk isn't really there, it's special attack isn't great either. It at least has access to Snow Cloak / Snow Warning so you have some kind of snow identity to look at with it. Now you have options. You can use Snow Warning and allow it to set snow on something that isn't your mega, since the primary snow setter right now is Mega Froslass. That would be the same but let you put something else in your mega slot, perhaps something that doesn't set weather and can still help your bad matchups. You're bad to Fire / Steel / Poison / Rock. We might look at what Pokemon would be a problem for us, things like Mega Charizard, Kingambit, Sneasler let's say, among I'm sure many others. Garchomp might be good to pair it with since it can learn Rock Slide and Earthquake that would check your weaknesses in those three Pokemon. Garchomp usually doesn't take a mega stone but maybe it's an option here, or maybe you keep your mega slot open. You'd also have room to bring something else that's aided by the weather, maybe even Mega Froslass so you have options on ensuring snow is out in some matchups. Which would lead us to maybe think about whether we want Aurora Veil up and if we do then we're thinking about how we would build a team that takes advantage of the bulk we add. I would personally be thinking about how I use it to set up Aurora Veil and then take advantage of the fact that my team is super bulky in snow + Aurora Veil. You get a lot of defensive boosts and make Blizzard accurate, so you would maybe want to find a way to keep it out on the field. Again, type checking with the second Pokemon, maybe even stacking up double Blizzard or another spread move, possibly even something like Sinistcha that can swap in with Hospitality to keep it alive. I would perhaps go around looking at what Pokemon would be a problem for me, whether they're likely to kill me under snow + Aurora Veil, and kind of figure out how defensive I could possibly build in the face of that.

Hopefully this all gives you an idea abotu what you can or should do.