Difficulty: Hard

The reason why she should be your first enemy is because required sacrifice for her isn't significant. Throughout the game you will be using only the greatsword. In this game it's better to deal more damage per hit than more damage per second. Also parrying is useful only in some bosses and can be done with any other weapon in the game. In conclusion, shield nerf isn't that big of a deal.

Difficulty: Medium

Here you lose 2 heals and healing will now be slow rather than immediate. I understand it's really important in some situations to get that healh on an instant but considering how important dodging and good damage is during a fight with him, he should be beaten in a second place. The only exception here can be Envious Levin Undok, it wouldn't really matter if you beat her before this fatass so that's totally up to you.

Difficulty: Very Hard

Sacrifice that has to be made in order to fight her result in a loss of supplies. You lose 10 spears, 4 bombs and both fire buffs. These aren't that big of a deal either. In most fights you are only gonna use your sword and eventually heals because spears and bombs deal really cheap damage and are generally not very useful. As for fire buffs, they cause health loss, so you shouldn't use them anyways since your health is priceless.

Difficulty: Medium

Your sacrifice here makes your attack power go down. He's a pretty easy boss compared to some of the others so you shouldn't struggle too much. Staying under his feet the whole fight should do the job. Also you don't need those instant heals or supplies in a fight with him so that's why he has placed fourth.

Difficulty: Very Easy

In order to fight him you have to sacrifice a very important ability to dodge and attack without exhaustion. From now on you will collapse whenever you try to perform any of those two actions with your stamina being at it's lowest. This ability was very much needed in bosses from one to four and Yordo is the easiest boss in the game so your previous nerfs mean nothing in a battle with him.

Difficulty: Easy

Your health is very important and sometimes that tiny % of it can determine the fate of the game. To fight Faiz Tilus you have to sacrifice certain value of your health and stamina causing you to get tired faster and die faster. He's also a pretty easy boss and again, you don't need those supplies or heals to win a clash with this guy. All you need to beat him is know the pattern (when to parry, when to attack, when to hide and when to run).

Difficulty: Easy

I decided to put him at the last place because to fight him your defence power gets decreased meaning you don't have that chestplate anymore plus you must sacrifice your ability to heal passively so no more running away from your problems. This is probably the worst disadvantage in the whole game which is why I think he deserves the end of the list. Actually it might not seem like it but in a matter of fact he is one of the easiest bosses here. After some tutorials you should defeat him with an ease even with all of those flaws of yours.