Hi. Maelstrom Engine can't use code from Storm Engine, since it will violate GPLv3 license:
https://github.com/storm-devs/storm-engine/blob/develop/LICENSE.txt
GPLv3 is copyleft license. If you want to copy some GPLv3 code to your project, then you need to open source it under GPLv3. Check this FAQ: http://gplv3.fsf.org/dd3-faq