Well first identify what you need with the entity, is it pure power ascent and knowledge. Or trials, discipline, and deception.
I have two entities I recommend.
Belial and Lucifer
Belial is the law demon, he will set up rules or trials expecting them to be difficult in order to prove your devotion and loyalty. He is also speculated to be a liar, but I believe this is due to practitioners faults. I´ve done some pretty ¨dumb¨ stuff while invoking Belial cocky is an understatement when it comes to this entity. I found myself stealing stuff, cussing out superiors, threatening the strongest people I know and um…taking on an entire Freemason Lodge. The people I thought loved me the most or have a deep connection with me have deep ties to this. If you want personal ascent and life redirection he’s the guy.
Lucifer is personal ascent but in a different way, he is much more ¨beginner friendly¨ because he doesn’t care about giving someone too much power. He will blast open all your chakras and won’t apologize because you asked for it. He is an angel so he has a reputation for helping with a little offering in return, often times asking for help or guidance from him is enough to see results. He is very similar to Jesus since he has no real trails in order to recieve the benefits of worshipping him or working with him. Lucifer gets trick once you become more adept, the light that he bears may become dim requiring you to shine your own light and guide others. Or stay in silence and navigate the dark nights in hell.