Chosen by Aliens, I Became an Ultraman Actor

I was sitting at home when a job came out of nowhere! The job requires no interview or even a resume, promises a lifetime of food and drink, and comes with powerful abilities like growing bigger or smaller, becoming extremely hard, and moving extremely fast... Xu Tianxiang has no choice but to accept this sudden offer. In a daze, he finds himself standing in front of an attacking monster. To be precise, he and the monster are positioned with him on top.