The Blood Legacy

I've read people saying this quest gives them problems (specially since you can get it at level 5) waiting till level 10 can help what with having a companion, but I was able to do this on my Inquisitor at level 7 and Warrior at level 6. It requires kiting from both classes more so for Warrior I found.

SI: After summoning the beast knock it back with Overload and walk backwards to the steps where you get the skull from using instant casts and Saber Strike. Once you get to the top of the stairs knock it back and use Force Lightning and anything range. When it reaches you walk backwards towards the door till you can use Overload again. Keep going back and forth and have a med pack ready, I needed one.

SW: As soon as you summon the beast back off to a range you can open with charge. Then walk backwards towards the steps constantly striking the beast the whole time. Use Force Scream as often as possible. When you get to the steps turn around and head back. There were times when I had to run away just to take a moment away from taking damage, but solo'ing him is completely possible. Once again keep at least one med pack ready.

good luck

Actually Retaliation (Riposte is the republic variant) is very inefficient at this stage. For the same 3 Rage you can also do a Vicious Slash which does a lot more damage. The only thing in favor of Retaliation is that it isn't on the GCD, but that advantage is outweighed (IMHO) by its lesser damage.

I like to keep Saber Ward and other defensive cooldowns as a panic button, but that's a matter of preference I guess..

I just killed him with my lvl 7 Sith Warrior. It's a tough fight, but doable.

Pop a stim first; I used a strength one.
Make sure you have both buffs activated (Shii-Cho Form and Unnatural Might)
Try to max out your Rage before starting by clearing some trash.
Keep a Minor Medpack in your bar; you will use it.
As soon as you soak the skull in blood, run to the side of the room so that you can use Force Charge as your first attack.
Pop Saber Ward as soon as you engage him.
Use Force Scream as often as it's available; alternate Retaliation and Vicious Slash, and Assault as needed to boost Rage.

Using these tactics, I didn't have to kite him at all.

Tried this quest without a companion with me at level 6,7 as a sith inq...and it didnt work out..then i get back in with a companion and killed it without using a medic pack.
First attack i knocked him back, get back a few steps and light him while he target your "pet".

Hope its help.