Sure, let's refine and expand your story a bit:

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(Guys, if you have suggestions, then don't shy off and suggest as you like—ideas about female characters, abilities or things the MC wins from gacha, or what impact these females can have on the Marvel world timeline, or which location of the universe they should be summoned to so they can show their expertise or naughtiness.)

"Ugh, where am I? What happened to me?" A man suddenly opened his eyes and put his hands on his head to stop the sudden sharp pain. After a while, his mind calmed down, and he checked his surroundings, finding himself in a normal room. In this room, there was an air conditioner, a bed, a table, a television, a chair, and other normal things every living human has.

He saw a picture framed on the table. Extending his hand, he picked up the picture and looked at it carefully. "This woman, Pepper Potts? My adoptive sister? Or am I her adoptive brother?" Montu murmured to himself, looking at the picture where a woman and teenager were standing next to each other and smiling lightly.

"Well, first, categorize these messy memories," Montu thought, putting the picture back in its place. He sat in the Lotus position and closed his eyes, thinking deeply. "Hmm, so Thanos has wiped out half of the universe's population, and a month has passed. It looks like I'm in the movie version of the Marvel world," Montu thought to himself, opening his eyes.

"So, do I have a golden finger after being transmigrated to the Marvel movie version?" Montu thought to himself calmly, not panicked as it would only make his mind more disruptive. Suddenly, a tablet materialized in his lap. Montu picked up the tablet and put his thumb on the fingerprint animation in the middle of the screen at the bottom of the tablet.

[Host bound successfully]

[Welcome host to this unnamed system]

"Your name will be Ava," Montu said.

[Name Ava has been taken successfully]

[Hello host, Ava is at your command]

[First function of this system is to summon female characters from fictional worlds from your previous life into this life in reality]

[But host must have special energy of this world to summon those female characters as charge]

[After summoning, you will get a chance to perform a gacha where you can gain any one thing from the summoned female character, either her underwear or her most powerful ability]

[Summoned female characters will be summoned in this universe at different locations randomly, so please find them yourself]

[summoned characters will be loyal to the host, but they will not take the initiative to come to the host, as they have free will. they love the host, but the host should also show your love to them genuinely]

[Please note that the host has the power to throw these summoned characters back to their world if they try to hurt the host, but the host will also lose the things or abilities won by gacha from those female characters]

[Host, after you take these female characters into your harem, you will get one more gacha chance]

[Again, Ava is at your command, host]

"What a strict system, everything is balanced. I will have to rely on myself to win the hearts of those women to become a truly powerful man in this universe," Montu said to himself while playing with the tablet in front of him. The tablet had basic functions every tablet has, like a camera, storage, calling, video calling, etc.

Suddenly, the room's door opened, and a woman entered. "Didn't I tell you yesterday to be ready as today is the day I will marry?" the woman complained as she removed the blanket covering Montu's half body, dragging him out of bed and pushing him into the bathroom.

"I know, sister. Just wait ten minutes, I will be ready," Montu said with familiarity from his memories. Both of them arrived at the venue where the marriage would take place. Pepper quickly changed her clothes and waited for the auspicious time. After a while, someone came and informed them that it was time. Pepper nodded to Montu, and he nodded back to her, extending his hand. She put her hand in his, and they walked slowly toward the venue and entered it.

There were chairs on both sides, and many famous characters from his previous life could be seen, but Montu ignored them as his favorite character was waiting ahead. Yes, it was Tony Stark. Montu brought Pepper near Tony and the church father, then stepped aside. The church father started the prayers and then let Tony and Pepper promise to each other. After a kiss, the wedding was successful. Montu was standing in the hall, looking at everyone talking to each other with some happiness.

"Hello, handsome. What are you doing in the corner? Why don't you go and meet the famous heroes? At your age, you should be a fan of theirs," a redhead said, finding Montu drinking juice and looking at everyone but not taking a step forward to talk with anyone in the corner. She approached Montu with a mischievous smile on her face.

"I'm not good at these gatherings and don't like conversations with strangers. Well, compared to many of them, I may want to have a conversation with you more than anyone, Miss Natasha," Montu replied with a smirk.

"Oh, so you wanted to hook up with me, but sorry kid, you're still young in my eyes," Natasha said, raising her eyebrows.

"Really? Then why don't you give me a chance? If not, maybe you will regret it in the future, and we can form a family, as I'm a bit jealous of Stark," Montu said with a sigh.

"Here you say you want to start a family with me, but there you're still drinking juice like a kid," Natasha said.

"If you want, maybe I can drink something tastier and stronger," Montu said and signaled to the waiter, picking up a whole bottle of whiskey.

---

6 o'clock in the morning.

Montu woke up slowly and sat on the bed, looking at Natasha, who was still sleeping calmly. "How can I heal her?" Montu thought to himself. "Hey Ava, can I get something which can heal her inability to give birth to children?" Montu asked in his mind.

[Yes host, you can, but the summoned female character must have an object or skill which can heal]

"So Ava, do I have any beginner-level benefits?" Montu asked.

[Yes host, You have one summoning opportunity, but the character summoned will not be very powerful]

"Really, what a good system you are. You will not take the initiative until I command you. Okay, perform the summoning," Montu complained a bit and then ordered Ava.

[Summoning starts]

[Character Summoned Successfully]

[Character summoned is...]