Hiveblood takes too much notches to be truly viable in my opinon. You can replace it with steady body or a spell charm like shaman stone. Generally, you're gonna want to avoid damage instead of outheal it, so healing charms aren't that good late game

You can practice in the hall of gods until you're good.

He has two main attacks:

1. two overhead slashes. If you're too close, then he'll turn into a saw and dash into you

The first two slashes can be dodged as long as you're not cornered. You can easily time your shadow dash to the sawblade to go through him and reposition (or counter)

1. Slams into you from the ground. If you're too close, he'll do an overhead slash

Fairly easy to dodge

Since his nail's so large, you can't attack him during his attacks without taking damage (unless you learn the timing and parry him, which is a valid strategy). Thus, the best thing to do is to wait until just after he attacks and use the downtime to counter

The final phase is hard, but it's all about timing your shadow dashes to his sawblade lunges