Mtk-su Failed Critical Init Step 3 'link' -

Do not use ancient versions like v18 or v22. Download the latest official build (usually v33 or r24) from the original XDA thread. Place it in /data/local/tmp and set permissions:

./mtk-su -v # Verbose mode – watch where it fails ./mtk-su -s # Force a different escalation method ./mtk-su -f # Force exploit even if checks fail (risky)

Your device has a security patch newer than March 2020.