Ni ButterflyEffect Weijie is a cyber athlete from China who competes on the competitive scene of the Dota 2 discipline as a midranger. His signature heroes are Shadow Fiend, Ember Spirit and Templar Assassin.

ButterflyEffect began his cybersport career in the fall of 2018, joining the youth Dota 2 team of the Chinese organization Invictus Gaming. Thus, the guy began to perform under the tag of the iG.Vitality roster, for which he played for four years. During this time Ni won such tournaments as VARENA DOTA2 League Season 1, Feng Ye Professional Invitational Competition Season 2 and Asia DOTA2 Master League Season 2, as well as took silver at China Future Cup, The Challenge Cup Season 4 and JJB Spring Cup Season 2. In addition, ButterflyEffect occasionally played for Invictus Gaming as a substitute.

In December 2022, Ni joined the Team Cloud roster on loan, where he won a small event at Golden Age Season 2 and played at the DPC CN 2023 Tour 1: Division II. Then ButterflyEffect represented Holy Grail tag for some time, and a little later the Chinese cybersportsman joined iG.Vitality again. In a familiar team the guy took part in the third round of the lower division of the rating league Dota Pro Circuit 2023.

Ni spent almost the entire year 2024 as a member of the Chinese team kev. Under this tag, he qualified for the Elite League Season 1, but in the main part of the tournament, the team finished in last place. ButterflyEffect also participated in the closed qualifiers for the Riyadh Masters 2024 and The International 2024, but did not achieve high results and did not make it to the tournaments. In June, Ni joined Evil Rabbit, with whom he took 1st place in the qualification for the Elite League Season 2.