Tatsumaki meeting Izuku sounds like such an interesting plot setup because Tatsu’s mentality she got as a child, (“don’t bother waiting for a hero, save yourself,” and “saving others is pointless,”) run directly counter to Deku’s philosophy he gained as a kid (“anyone and everyone can be saved,” and “you should always maintain hope.”) Both of which were inspired by a hero (Blast and All Might respectively).
Not to mention as heroes they cover each other surprisingly well. Izuku is the physical close range combatant who has a few long range options but mainly focuses on the fundamentals and versatility based on that, whereas Tatsu is a long range psychokinetic who plays keep away and uses her powers in creative and complex ways.
Their personalities, too. Deku is kindhearted and humble, Tatsu is haughty and kind of bratty. Izuku is mature and forward thinking, Tatsu is a tad shortsighted and indulges in minor tantrums. Where the former never underestimates and constantly respects and compliments his enemy, the latter belittles, has a superiority complex, and is nearly incapable of giving anyone proper credit.
What I’m saying is they’re surprisingly synergistic and would be peak fiction.