Hearthpwn

This deck gets wrecked so hard against spell hunters 

Can't craft it if you don't own Kara xpac

I dont have medivh vallet what should i add to this deck?

Yeah, he's hacking for sure. I can tell by the screenshot.

Just wanted everyone to know what a great user this guy is, he personally helped me with my deck.

There is no Sylvanas or N'Zoth in that deck. Both are very optional for rogue. Thalnos, on the other hand, is essential for any rogue deck, but doesn't see much play outside of it (freeze mage is out of meta and yogg druids tend to skip it) so only craft it if you really enjoy playing rogue, it's pretty safe to say it will always be played. Kobold geomancer is a bad card and it is not recomended to run it, shiv is generally considered more suitable replacement, but nothing really compares in versatility with Thalnos.

I believe Sylvanas doesn't easily find a place here, while N'Zoth does. We have several impactful cards with deathrattle. You can try playing both of them, as their combo is just great, but if I was to choose, I guess I'd pick N'Zoth for the slightly better late game it provides.

And indeed Geomancer is an ok replacement, but I'd test Loot Hoarder.

Sylvanas if you're not rushing a N'Zoth deck.