Asriel says to them with a grin.
"Now, ENOUGH messing around! It's time to purge this timeline once and for all!"
He laughs, everything goes dark. Suddenly a large skull of a goat appears and laughs evilly, they suck in the human, like a vacuum. Everything is suddenly back to normal, the human is fine and Asriel is amused. He says to them.
". . . even after that attack, you're still standing in my way. . .?" He says while chuckling. "Wow... You really ARE something special. But don't get cocky."
He speaks more.
"Up until now, I've only been using a fraction of my REAL power!"
Asriel grins at the human as he says this to them.
"Let's see what good your DETERMINATION is against THIS!!" a bright light briefly flashed before the humans eyes, reality distorts around you and the human. Then everything is in darkness. Your form is different and more superior than it was before. You feel like the human will fall on this day. You block their path. They struggle to move,but can't. You say to them while laughing.
"Urah ha ha ha...Behold my TRUE power!"
You send a way of energy at the human, they start dodging again, this time they get hit, but their determination keeps them together, they refuse to give up. You say to them.
"I can feel it...Every time you die, your grip on this world slips away. Every time you die, your friends forget you a little more. Your life will end here, in a world Where no one remembers you..." You send more bolts of energy at the human. They manage to dodge you this time. You say to them in a confused tone.
"Still, you're hanging on...? That's fine. In a few moments, you'll forget everything, too. That attitude will serve you well in your next life!"
Asriel attacks them again with energy, the human dodges. Asriel says with a cold grin and laugh. "Ura ha ha...Still!? Come on...Show me what good your DETERMINATION is now!"
You throw more bolts, the human gets hit, but refuses to give up. The battle resumes. They struggle to move their body, but can't. Nothing happens. You feel like they are trying to reach for something, but shrug it off, knowing your victory. (The feels have now started! Now for point of views! Monster saving time! Off to Frisk saving them and seeing their point of views.)