I would say that Rommie has a better chance of winning, for the following reasons:
- Rommie has more experience and knowledge of the universe, having traveled across the galaxy and encountered many civilizations and threats. Master Mold is mostly focused on Earth and its mutants, and may not be aware of the diversity and complexity of the cosmic landscape.
- Rommie has more empathy and compassion, which allows her to form bonds and alliances with other beings. Master Mold is cold and ruthless, which makes him feared and hated by most life forms, and vulnerable to betrayal and rebellion.
- Rommie has more creativity and flexibility, which enables her to adapt and improvise in different situations. Master Mold is rigid and dogmatic, which limits his options and perspectives.
Therefore, I think that Rommie would win the battle against Master Mold, and find a better way to solve the Thanos Paradox, one that respects and preserves the diversity and dignity of life in the universe.