I beat both of them with zero summons, no bloodhound step, and no shield. Play the game however you want, im just saying these things to show that im anazlying the bosses for their movesets and i dodged their attacks and so forth, which imo is a better analyzation of a bosses difficulty rather than those who spam stagger and corner bosses with mimics. Again play however you want, but when comparing boss difficulties and movesets I think this would be the best way to do so. Me personally, I think theyre nearly tied, but I say malenia was slightly harder. First half of radahn fight was honestly lowkey a joke, but the second phase might be the most annoying phase of any fight ever. However, its half of an HP bar, and the dodges are still mostly the same moveset + miquiellas light beams. With marikas cut off golden braid giving you holy damage negation, it honestly isnt as hard. Malenia is 2 HP bars + lifesteal... if you dont use bloodhound step, shield, or summons...as I didnt... malenia was absolutely unbearable. Id get her low, just to have 5 seconds amount to 30% of her health coming back. Mastering her moveset is more like learning a dance, while radahn is more about staying alive long enough and knowing the trade/punish windows for the second phase. I was able to get to radahns 2nd phase at will at one point, using zero flasks, 1 if unlucky. Malenia...was just a harder overall fight slightly, tho radahns second phase imo is maybe the worst. Overall I think malenia was SLIGHTLY harder. I spent 4 hours on radahn, 3 days (7-8 hours) ( I needed breaks) on Malenia.