General Strategy

The best way approach Renea is to think of her as a “wavedash” character that slides into whatever range she needs. She has many ways to do this, including:

Dive (preferably EX)

Strafe Fire

Flare (which also has an “Attacks at range 1 don't hit you” mechanic)

Lethal Force (both as an attack and a transformation)

Anticipation (both as an attack and a boost)

Cross (both as an attack and a boost)

Assault (both as an attack and a boost

Before Exceeding

While in normal mode, you want to take advantage of your face-down Continuous Boosts. When you do play face-downs, it's usually smart to wait for the opponent to declare a strike. Keep these two facts in mind:

If you declare a strike, you will activate all of your face-downs before your opponent places their attack.

you will activate all of your face-downs before your opponent places their attack. If your opponent declares a strike, they will have to guess not only your attack but also your face-down Continuous Boosts.

With the confusion you are causing your opponent, you can easily pull off a transformation or two, which will not only make Renea more powerful but will also give you a discount on Exceeding.

Money in the Bank

When you Exceed, you lose your face-down boost ability but you get a shiny new Briefcase with three of your opponent's boosts from the discard inside! And when you hit your opponent, you get even more of their boosts into your Briefcase.

With this briefcase, you can boost with one of your opponent's boosts attached to the briefcase once per turn. If that boost doesn't cause a strike, you get a second action! This makes it easier to exploit Renea's boost-focused transformations like Double Down (Strafe Fire).

The Conspiracy Combo

Conspiracy Unearthed is a boost that can take a peek into the opponent's hand and make them add one of those cards from there to the gauge. If you have this as a face down boost and attack, you get to look at their hand, remove a card, and then immediately set your own attack.

The obvious combo is face-down Conspiracy Unearthed, then on your next turn initiate at range with Called Shot. Your opponent can interfere with this if they play brave and attack into your boost, so have a backup plan ready at your preferred range.

If they do attack first, they will set before you get to see their hand. In this case, try to predict their attack by looking at what remains in their hand. Use Dive, Lethal Force, or Strafe Fire to reset range, so you can still follow up with the Called Shot as planned to do more damage. The Reading and Parry boosts (on Focus and Block) can take advantage of your knowledge as well when Called Shot isn't available.