A few minor changes that would make Atlas amazing.

[Vitamin.Ex]

After Atlas got his rework I thought he was really fun to use, I have been using him ever since. But, there are a few changes that would make him a lot better than he is now. 

For starters, Tectonics. The ability should create Rubble when you roll it, or at least create Rubble when it hits someone and explodes. I know they added Rubble drops when it's destroyed, but, that rarely happens if you're using it to roll. Waiting for it to be destroyed just doesn't fit the fast-paced play style of Warframe and is ultimately useless.

Next on the list is Petrify. For a passive primarily built around spamming Petrify to keep his passive armor up, the skill cost is quite high in my opinion. Even with max efficiency, it still costs close to 20 energy to use. If you're trying to keep your bonus armor up, you'll be draining your energy quick. I feel it should cost half of where it is now.

As for his passive, I feel it drains too fast. If the armor drained just a bit slower, it would allow you to keep his bonus armor up without needing to spam petrify as much while giving you enough energy to use your other skills. Another thing I find that needs a change is how Rubble only gives armor if you're at full health. I think it should give health/armor everytime you pick it up regardless if you're missing health. Or, make him immune to slash procs if he has any bonus armor up. With slash procs ticking away at your health it is sometimes hard to get any armor since all the Rubble pickups are just giving you health and no armor.

 

These suggestions aren't major changes, just small adjustments that would make him more balanced and give all his skills the synergy he needs.

[AceDeus]

Change his Tectonics to form a wall around him creating an arena that forces enemies to climb into the arena so Atlas has better close combat potential