It can combo off of a Dtilt at low percents for some insane damage. You may need to pivot Fsmash charge, since Dtilt can shift them behind you sometimes. If you see them popping out of the top, tilting the Fsmash up can usually catch them before a lot of characters can interrupt you or it can catch the start of their jump. If they airdodge, well then they've likely just airdodged into the ground and can't punish you properly anyways.
Other than that, it is great at covering get-ups. If you run to the edge and pivot Fsmash charge towards the stage, it covers every option except wait or drop down + aerial. Covers jump, attack, roll, and standard get-up. Otherwise, standing at perfect spacing away and charging can catch roll getup, and releasing the smash can possibly catch jump and standard. The advantage to the second option is that if they wait, you can angle the smash down and hit with the tipper.
Finally, the charge box is a transcendent disjointed hitbox which means it can't clank with anything and isn't a hurtbox. As such, It can catch a lot of horizontal recoveries before they hit Corrin and stop them in their tracks. For example, Fox's tend to love Side B-ing onto the stage, but if you throw out the charge, It'll catch them and lock them in. Other good moves to catch with this; Ike's Quick Draw, Diddy's Monkey Flip, Bowser Jr's Clown Kart, Ganondorf's Flame Choke, Pikachu's Skull Bash and Quick Attack, Luigi's Green Missile, Lucario's Extreme Speed, etc.