Here are some options, depending on the context:
For the sense of "reckless" or "unrestrained":
* Unbridled: This emphasizes a lack of control.
* Unrestrained: This highlights the absence of limits.
* Indiscriminate: This suggests a lack of selectivity or discrimination.
* Headlong: This emphasizes a rush or impulsiveness.
* Profligate: This suggests wasteful or extravagant behavior.
For the sense of "lustful" or "immoral":
* Licentious: This implies a lack of moral restraint.
* Lascivious: This emphasizes a lustful or sensual quality.
* Debauched: This suggests a corrupt or depraved state.
* Lewd: This implies a vulgar or indecent nature.
For the sense of "cruel" or "malicious":
* Callous: This suggests a lack of feeling or empathy.
* Vicious: This emphasizes a cruel or savage nature.
* Sadistic: This implies a pleasure in inflicting pain.
The best choice will depend on the specific meaning you want to convey and the context of your sentence.