Maybe Naruto from Naruto could be a crossover character. His ninja skills and Ichigo's combat abilities could create some unique fight scenes. Also, their different ideologies about friendship and power could lead to some great character interactions.
Luffy from One Piece could also be a great crossover character. His Devil Fruit powers and Ichigo's powers would clash in a really fun way. And Luffy's carefree attitude would contrast with Ichigo's more serious nature, leading to some humorous and interesting situations.
One potential antagonist could be an ancient evil that is awakened by Ichigo's newfound power. This entity might see Ichigo as a threat or as a means to achieve its own dark goals.
One potential crossover character could be Goku from Dragon Ball. Since Naruto has godlike powers in this scenario, a meeting with Goku, who also has superhuman strength and abilities, would be very interesting. They could have a friendly sparring match or team up against a common enemy.
Rukia could be one of the characters. Since she has a deep connection with Ichigo already in the original series, it would be easy to develop a more romantic aspect in the harem setting. Orihime is also a likely candidate, as she has strong feelings for Ichigo. And from other animes, a character like Saber from 'Fate/stay night' could be interesting. Her noble and powerful nature would contrast with Ichigo's more rough - around - the - edges personality.
One potential character could be Naruto from the Naruto series. His ninja skills and strong will could create an interesting dynamic with 'godlike gon'. Another could be Goku from Dragon Ball. The comparison of their power levels and fighting styles would be really cool. Also, maybe Light Yagami from Death Note. The clash between 'godlike gon's sense of justice and Light's more morally ambiguous actions would make for an exciting story.
Another potential character is Harry Potter. His wizarding skills and knowledge of magic could be a contrast to Naruto's ninja abilities. Imagine Naruto in Hogwarts, learning about magic while also showing off his ninja moves. They could also face a threat together, like a dark wizard who is trying to use both magic and chakra for evil purposes.
In this fanfiction, characters like Luffy from One Piece might be involved. Luffy's carefree yet determined nature would contrast with Ichigo's new god - like presence. Also, characters from the Bleach universe itself could have new relationships with Ichigo. For instance, Aizen might see Ichigo's godhood as a threat or an opportunity, leading to a complex plot development.
In a crossover with Fairy Tail, Lucy could be part of Naruto's harem. She is strong - willed and might be attracted to Naruto's godlike power and his kind heart. Also, from the Naruto universe, Hinata would surely be in the harem as she has always had feelings for Naruto.
Another potential character could be Naruto. Naruto has his own set of ninja powers and a strong will. If he were in a crossover with Vegeta, their different ideologies about power and friendship could clash or they could learn from each other. Naruto's ability to never give up might inspire Vegeta in some ways, or Vegeta's raw power could amaze Naruto.
If it's a crossover with the One Piece world, Blackbeard could be a potential bad guy. His ability to steal Devil Fruit powers and his ambition to become Pirate King could lead to a clash with Gohan. Gohan's pure - hearted nature would be in opposition to Blackbeard's more devious ways, and their battle could be epic, with Gohan's ki powers against Blackbeard's dark powers.
One possible ally could be a powerful mage from a different anime in the crossover. This mage could help Ichigo understand the strange magic or energy in the new world he is stuck in. Also, Uryu might be an ally. His Quincy abilities could complement Ichigo's powers in Mugetsu form as they face new threats together.