Complex sentence: As a result of the experiments done on him, Blood Stalk classifying him between Hazard Levels 2 and 3, Ryuga now has increased physical strength which, combined with his natural fighting abilities, makes him a powerful fighter.
Split into simpler sentences: As a result of the experiments done on him, Ryuga now has increased physical strength, with Blood Stalk even classifying him as having the power of Hazard Levels 2 and 3. This, combined with his natural fighting abilities, makes him a powerful fighter.