Ragnarok Mobile - Hela Gameplay. Quick Dummy Damage Test 

need a alchemist job to unlock hela?

Yes

That dmg is from the summon unit?

Yes. Hela can summon up to 2 dogs and is capable of dealing decent magic damage per attack.

Poison damage.

I see. It's quite high damage. Thanks

It does a lot of damage esp at high stacks (15 stacks max)

That is life steal from summoned dogs hence heal is based on matk.

Though hela has some other ways to heal. I recommend to watch other yt video of hela that has full detail of her skill kit.