pulsar rover
The Traveler has a mythical portrait (red), and is seemingly implied to be extremely powerful and probably the only mythical Hero in the game (though I personally think The Dark Lady should be/should have been the first mythical Hero), though while they are much stronger/more fun than a lot of the starting heroes in other gatcha games, they still ultimately fall short of even some epics.
Just to make them a little bit more relevant to people who still want to stick it out with them, the ability to change Schools from the Support default would be pretty cool. Since they shift to either Fire, Lightning or Ice, being able to shift to Wild, Dauntless or Frost, with minor tweaks to their abilities to synchronize well with those schools would at least make them a bit more viable, even if ultimately fated to be replaced late game.
As a quick example, the fire kit with Wild could be modified to something like (whenever they or an ally roll >=5, they reapply the 20% attack up to allies for 5 seconds (or maybe just when rolled on an Ultimate). I personally am a fan of the Chain Break mechanic, and it'd be pretty insane to see the damage decrease by 50% be mitigated by a higher dice roll on the ult (so if you roll a perfect 6, the extra attack actually does full damage or 75% damage), but I do realize how strong that is - would be so cool tho 🥺.
A similar thing with reapplying Attack Speed Up 2/Defense Up 2 and dauntless basic attack thresholds/Frost proc thresholds, or a similar focus on enhancing the ult, like for Frost the shield to each ally has a chance to frost the enemy attacking it, etc.
Of course the school bonus of having 2 or 3 of the same school would apply for the player character now, and the ability to switch to Support for any of three elements would still be possible.