You can become a Titan Shifter in Attack on Titan Revolution (AOTR) after you unlock Titan Shifting. This is a big move, as it transforms you into one of the main titans in the series, namely Attack Titan. However, since you’re getting such a powerful power that can almost instantly take out most opponents, it’s not something you’ll be getting for free. So here’s the item you’ll need to do it, where to find it, and how the skill tree works.

You'll need the Attack Serum which will allow you to spend Skill points on your Titan Shifting Ability. Here's how to get it:

Now, when you press the button for your assigned skill, you will perform Titan Shifting and transform into an Attack Titan. With this skill at hand, dealing with titans becomes a lot easier.

That’s all about how to become a Titan Shifter in AOTR. For more help with this game, you should also check out how to increase potential and its codes.