>>1759505
Alright first off, you hit 3 tackles against Magna's head. If you had done 2 more he would've KOd and that's a free full charge. Just do two more of those roll tackles that you did at 0:16

Like this guy said >>1758330 you against wasted a full charge tcs opportunity after the arm break. Idk if you're not reacting fast enough or not or just thought it was out of range, either you need to try to internally keep track of the arm's break threshold and make a calculated commitment to perform an attack that breaks > immediate full charge, or you need to limit test your range more because greatsword's range is much higher than that

Lastly Magnamalo can start out in 3 modes which all give him different AI patterns, based on what part of his body he infuses with hellfire, plus the body part that's infused becomes much weaker
>head
Just reset if he does this one because not only does he get to rage mode a lot faster than the other 2, the first 2 attacks he does are spastic as fuck and you're not gonna find a decent opening
>tail
Starts out with a lunging tail stab (great opportunity to hit a TCS on his arm), then throws hellfireballs (very easy to perfect evade), then does a tailslam (long downtime that will let you hit a fat charge)
>arm
Best one to start out with because you want to be aiming for the arms in the first place, not the head. There's 2 topples you can get out this and if you wanna minmax your damage you really need those full charge attack windows. Also very abuseable, he will always start with that arm stomp at 0:03 and it has a tiny hitbox. You just have to roll left once and then you can hit a full charge on his arm and then you're basically halfway towards toppling him. After claw stomp he will always do the explosions, which is another easy opening granted you're positioning for the purpose of attacking his arms in the first place. See picrel to see where it's save to stand. You can do 2 full charges in a row this way