What if someone uses Jesus name against you for evil, what would happen, and what should you do?
Bless those who curse you. Then pray. There are many prayers at our disposal. God wouldn't do anything to you if a person misuses His name for evil purposes. Don't be fooled.
Ex:
Prayer to the All-Holy Trinity
The Father is my hope; the Son is my refuge; the Holy Spirit is my protector. O All-holy Trinity, glory to thee.
The 'Jesus Prayer'
O Lord Jesus Christ, Son of God, have mercy upon me, a sinner.
The Trisagion Prayers
In the Name of the Father, and of the Son, and of the Holy Spirit. Amen.
O heavenly King, O Comforter, the Spirit of truth, who art in all places and fillest all things; Treasury of good things and Giver of life: Come and dwell in us and cleanse us from every stain, and save our souls, O gracious Lord.
Holy God, Holy Mighty, Holy Immortal: have mercy on us. (Thrice)
Glory to the Father, and to the Son, and to the Holy Spirit: now and ever and unto ages of ages. Amen.
All-holy Trinity, have mercy on us. Lord, cleanse us from our sins. Master, pardon our iniquities. Holy God, visit and heal our infirmities for thy Name's sake.
Lord, have mercy. (Thrice)
Glory to the Father, and to the Son, and to the Holy Spirit: now and ever, and unto ages of ages. Amen.
Our Father, who art in heaven, hallowed be thy Name; thy kingdom come; thy will be done on earth, as it is in heaven. Give us this day our daily bread; and forgive us our trespasses, as we forgive those who trespass against us; and lead us not into temptation, but deliver us from evil.
Through the prayers of our holy Fathers, Lord Jesus Christ our God, have mercy on us and save us. Amen.