Rise of the Tomb Raider

This shouldn't be too difficult - there are 9 challenge tombs, and you should have learned how to beat each one over the course of the game. Even without using cards, simply beating each level quickly should get you a time bonus big enough to get the gold - if you can shoot a few lanterns and keep a decent chain going, great - but not necessary.

For the last gold, the easiest location is Path of the Deathless - it's super-short, and all you have to do is kill around 15 zombies. If you can do it all without getting hit and keep the combo going, the gold is yours - this is easier than it might seem, since you'll have plenty of poison arrows, which 1-shot zombies.

You don't need to be good at fighting the Deathless, though - you can use cards to get over 200% bonus - focus on ones that make you take more damage, but don't make enemies tougher. I used 'no bandaging', 'bleeding', 'weak against fire', 'silenced weapons' - the trick is to get a solid combo going before taking the rope line down to the fighting arena. If you grab every possible item and pick up every wisp you should have a 20 multiplier - run to the ropeline, but don't jump on it yet. From that perch you can see a couple of lanterns below you, and five scattered around the ruins in front of you - all of the visible lanterns can be shot with your assault rifle if you're calm and aim carefully. Once you've hit them all you should have well over 20K - and since you only need 30K to get gold with a 200% multiplier, you can jump on the rope and head over to the fight knowing it's a mathematical impossibility to get less than gold - each deathless soldier gives you 1000 points at this difficulty, so even if you can't get a combo going at all, just killing all of them will get you the points you need. Since there's a checkpoint at the start of the fight, you can restart as many times as you like and still easily get to the point count you need.

I used PowerPyx's All Challenge Tomb locations video guide for 9 of these, and then Siberian Wilderness which is far easier than facing a load of the Deathless Army
Below are links to the 9 tombs and Siberian Wilderness videos I used, all credit belongs to them: