This challenge is ligature.
End of challenge I could find **=** so I thought of this is made of Base64.Using [Base64 Decoder](https://tool-taro.com/base64_decode/) you can see Binary sentense.And you use [Binary to text](https://rakko.tools/tools/75/) you can get Flag.

Original writeup (https://312k.github.io/312k-blog/post/post6/brixelctf-312k-eng/#shit).