Kiryu gains experience points (EXP) by defeating enemies, completing missions (main and substories), and engaging in various activities. EXP contributes to leveling up Kiryu's core stats: Strength, Agility, Spirit, and Heat. Each level-up grants you ability points.

Access the 'Abilities' menu from the pause screen to spend these points. Abilities are categorized into:
- Battle: New combat moves, increased damage, improved defense.
- Heat Actions: Unlock new, powerful finishing moves.
- Body: Increase maximum health.
- Soul: Increase maximum Heat Gauge.
- Tech: Improve various aspects like item effectiveness, running speed, or mini-game performance.
Prioritize Battle and Heat Actions early on to make combat easier. Investing in Body and Soul will increase your survivability. Don't neglect Tech abilities, as some can significantly improve your quality of life or mini-game scores. Experiment with different builds to find what suits your playstyle.