I personally don’t like the concept of Mythrons and think the Devs should lower their playabilities to around the level of Nemeton or Xor Xull. The reason why is because if we actually want them to viable, they have to match the power level of control decks that have or will exist in the future in order to be viable but the problem with this is that you inevitable will end up making the Mythron objectively stronger or weaker than actual control decks for the simple facts that Mythrons are infinitely more consistent due to always being in your hand (as well as lowering required amount of cards in your deck to 38 but that is besides the point).
I point Nemeton as the best example of what I believe a mythron should be more like because, despite it always being in your hand, it is far less consistent due to having to shift its gears around how fast or slow it plays depending on its match up. In addition, it has to search for the right cards in order to fulfill the conditions of the Trail. This contradicts what most other Mythrons like Wanderer, Ox and Strategos who continue with their established gameplans regardless of the match up do such as either curving out until they reach their respective lategame goals or simply dumping a large amount of minions on the board until you have done this enough to summon Strategos.
I know some people will argue that Wanderer has to shift as well depending on the matchup which is true to an extent but for the most part, the plan is usually just drop your Wanderer when optimal and then overwhelm with overstated minions. The gameplan is dropping Wanderer when optimal whereas the gameplan for Nemeton is more how to even get the chance to drop Nemeton and your plan on how to do this will vary depending on match up.
Though perhaps the biggest reason why I criticize most Mythrons and even Nemeton is because, as a result of Duelyst opting out of rotation, the game will begin to and already has experienced power creep (see Lavaslasher and Brightmoss Golem or Krater and Skorn). Because of this never ending influx of cards to the pool and no restrictions to their use, cards like Ox and Wanderer and Nemeton will experience progressive albeit indirect buffs due to having better and better cards to add to their gameplan from each expansion.
An interesting example of this is Thunderhorn. Before Thunderhorn, many archetypes had a wide variety of 4 drops to choose from each 4 drop excelling in some specific plan rather than for general use but once Thunderhorn came in, many 4 drops were dropped in favor of this card and the result was better decks although a more oppressive meta fueled by Thunderhorn. In decks like Ox and Wanderer who are just missing utility minion in a few key slots, they will progressively get better as incidents like this go on. Coincidentally, so will Titan Lyonar as it functions very similar to Ox decks.
Because of the reasons stated above, I would prefer if most mythrons were nerfed to the point where playing them is just slightly above a meme if nothing else due to their consistency of always being in hand. Furthermore, Mythrons like Ox and Wanderer should be reworked completely as even nerfing them to 9 mana would do nothing if power creep makes even a singleton deck extremely powerful enough to last to 9 mana as well as an Ox deck filled with powerful utility minions.
Either this or rework the mechanics of Mythrons completely and bring them down to the consistency control decks Pre ToM (ToM=Trails of Mythron).
What the devs will release next expansion I really don’t know. I’m honestly concerned over whether this game can continue like this only releasing expansion once every 6 months. The meta for me has become very stale and we still have minimum 3 months left to go before the new expansion. It will have to be a very good one to make up for such a long wait or at the very least some exciting news. I am not one to say this jokingly, but I truly think I will get bored of playing this game if this stagnancy keeps up.