Level 54, you get Blood of the Dragon. At this point, it's only used to empower your Jump and Spineshatter Dive during your opener.
Level 56, you get Fang and Claw. Introduce 4th combos the ability to extend your Blood of the Dragon timer, to keep it up basically forever.
Level 58, you get Wheeling Thrust. They're saying "okay, we've introduced this mechanic, and this 4th combo alone makes your DPS a bit higher essentially for free.
Let's add a bit of challenge to the concept, to make it a bit harder to deal optimal DPS. Not too hard, you just have to pay attention."
Level 60, you get Geirskogul. This adds you having to manage Blood of the Dragon timers rather than having it be infinite with no need for you to pay attention or learn when you can get away with using a bit more time.