Some Relevant Statutes:
O.R.C. § 5321.06 - Terms and Conditions of Rental Agreement
O.R.C. § 5321.13 - Terms Prohibited in a Rental Agreement.
O.R.C. § 5321.14 - Unconscionable Terms.
An Introduction to Landlord-Tenant Law. - Ohio Legal Services
O.R.C. § 5321.16 - Procedures for Security Deposits.
Ohio Law Gives Tenants Security Deposit Rights - OSBA
O.R.C. § 5321.02 - Retaliatory action by the landlord prohibited.
O.R.C. § 5321.15 - Acts of landlord prohibited if residential property involved.
My Landlord Has Locked Me Out or Shut Off Utilities
Fair Housing Act
O.R.C. 4112.02(H) - Unlawful discriminatory practices (Ohio Fair Housing)
Housing Opportunities Made Equal (HOME) Publications
Both landlords and tenants may be entitled to recover damges, whether associated with an eviction action or in a separate case.
O.R.C. Chapter 5321 - (Provides multiple provisions about when damages may be collected)
O.R.C. § 1923.081 - Joinder of Claims