He won the fight via submission in the second round. He also became the final tournament winner as Bellator moves away from tournament era. Weichel faced Pat Curran on February 13, 2015 at Bellator 133. He won the fight via split decision. Replacing an injured Georgi Karakhanyan, Weichel faced Bellator Featherweight Champion Patrício Freire at Bellator 138 on June 19, 2015. Despite dropping Freire with a series of strikes the waning seconds of the first round, Weichel lost the fight via knockout when Freire rallied with a counter left hook early in the second round. Weichel faced Georgi Karakhanyan at Bellator 147 on December 4, 2015. He won by unanimous decision. Weichel next faced up-and-comer Emmanuel Sanchez at Bellator 159 on July 22, 2016. He won via split decision. Weichel faced Brian Moore at Bellator 169 on December 16, 2016. He won the fight via submission in the first round. Weichel faced John Teixeira at Bellator 177 on April 14, 2017. He won via split decision. After four consecutive victories, Weichel was expected to face newly crowned featherweight champion, Patrício Freire, in a second fight at Bellator 188 on November 16, 2017. However, Freire pulled out of the fight due to multiple injuries. Weichel eventually faced Patricio Freire in a rematch in the main event at Bellator 203 on July 14, 2018. He lost the back-and-forth fight via split decision. After the title fight, Weichel faced Goiti Yamauchi at Bellator 210 on November 30, 2018. He lost the close fight via split decision. As the opening round fight of the Bellator Featherweight World Grand Prix First Round, Weichel faced Saul Rogers at Bellator 228 on September 28, 2019. Weichel won the fight via unanimous decision as he rocked Rogers late in the opening round. In the quarterfinals, Weichel was initially expected to face Emmanuel Sanchez in a rematch in February 2020. However, the date got pushed back and they were next expected to face at Bellator 241 on March 13, 2020. However, the whole event was eventually cancelled due to the prevailing COVID-19 pandemic. The bout was rescheduled and took place at Bellator 252 on November 12. Weichel lost the bout via unanimous decision. Weichel faced Keoni Diggs on June 25, 2021 at Bellator 261. He won the close bout via split decision. Weichel faced Pedro Carvalho at Bellator 270 on November 5, 2021. He lost the bout via unanimous