[Marvel] Dimensional Warfare

A mercenary veteran gets transmigrated to another world which he has no predisposed knowledge of. Worse yet, he gets dropped in the middle of a battlefield. How will he survive and thrive in this new unknown world?-No harem-Badass MC with potential slight PTSDNote- I'll be trying to improve my writing every chapter as this is my first attempt in several years.I have no military background and no extensive knowledge, if I get any information wrong for my research, feel free to correct me in the comments and I will fix it shortly. I'm also only human and I may have some glaring mistakes. This is also my first time writing a first-person POV, and I appreciate any suggestions. :)Disclaimer - This is a fanfiction of marvel and they hold the rights to their characters and plotlines