I understand why you say Magnus is the best since he is the best chess player in the world, but penguin is better in ultrabullet for 3 reasons:
1. He has a lot more experience in insanely short time controls and his ability to make split second descisions is really amazing.
2. His full board awareness is crazy, when I play ultra usually I only look at one side of the board since things are going too fast. The fact that penguin can play blindfolded ultra bullet at a 2200< level is probably better than what Magnus can do m.twitch.tv/videos/281209804
3. After the first 2 points, Say if penguin’s move quality is worse than Magnus’ in ultrabulllet. Without a doubt he is faster than Magnus, and since the ability to move pieces fast is an important asset, I’m pretty sure Penguin’s dexterity is much better than Magnus’ ex. m.youtube.com/watch?v=tGvgXH_SQtU
In 30 sec I would say Magnus may be slightly better than penguin but definitely not in 15 sec. Penguin would beat Magnus in an ultrabullet match and I would be willing to put any money on penguin.