@benn1nat0rI use Nightcap to Shadow Sneak away when a Steam Blaster approaches or gets close to me, and move back a distance before attacking.
If I start to get damaged by the Steam, I quickly use Casting Shadows and Shadow Sneak to get away before reattacking. I have only ever used Fung Fu on Steam Blasters who are unaware of my presence at first.
I may also jump around erratically when fighting one.
EDIT: Typo.
@benn1nat0rIf you do not already do this with Nightcap, try moving and jumping in less predictable patterns so that your Steam Blaster foes find it harder to track them, or try and sneak past them, rather than trying to get away from them, that could also work.
I also find that the Thorn Apart Legendary Upgrade for Rose is really useful against Steam Blasters. You can use your secondary attack to instavanquish Steam Blasters with 4 or more orbs charged. Good luck getting away from that Steamy friends - it has homing and you have no time to heal! Rose in general is an excellent character against them because the Jinx can increase damage they take from all sources, Arcane Enigma can be used to get away from them or to your team, Goatify can render them almost useless for a short time, not to mention they already have low health.
In my upcoming Legendary Upgrades Guides, I will also add enemies that can counter the Legendary Upgrades, to make it easier to counteract them.
