Honestly this archetype looks about tier 3 to me. When you break it down the 6 cards trump revealed are only mediocre stats. The weapon is a 1/3, kvaldir is a vanilla 3/2, down with the ship is your standard 2 mana 3 health minion removal, and helya itself is a vanilla 4/4. Tomb traitor is the same as duskbreaker’s effect on enemy minions sure, but do you know what else it reminds me of even more? Shardshatterer mystic, which was part of demon hunter’s soul shard deck back in the day. Do you remember what tier soul shard demon hunter was? I do, because I played that deck quite a bit. It was consistently tier 3 throughout its lifespan.
The problem with this deck is that it’s really slow and none of the cards have a power spike. You don’t generate stupid unanswerable board, but instead plink your opponent with tons of pinpricks over time. An aggro deck will probably kill you through board long before you get them to draw the curses (enrage warrior or pure paladin would murder this deck), and blood DK will just heal itself with its infinite lifesteal cards … not to mention that’s a deck that actually does run steam cleaner.
The whole archetype looks fun, but bait. Pretty sure we have a solid tier 3 deck in the making. It’ll be one people complain about when they lose to it, and it’ll be all over lower ranks, but it won’t be good and at higher ranks it’ll vanish completely.