2 traumata for 3 XP don't look great at first. You can trade 5 XP for healing one trauma in the interlude after "Threads of Fate", albeit I think hardly anybody would do this. But XP even before the first scenario are most powerful. You will have the cards you purchase from them for 8 scenarios (not accounting side stories). However, I see options, how to net gain quite more than that from this card.
Like already mentioned by Pawiu14, Calvin might be interested in the traumatas themselves. I'm not sure about that. I have not played him yet, but by experiences from coplayers in "The Forgotten Age", I've seen it can be a clutch to get him through this campaign, so starting right off the bat with additional ones to what you will get from your weakness, might be rewarding at first, but risky later on. But in a campaign, that doesn't dish out traumata in interludes, this should be a whole different thing. Starting Parallel Roland with 8 XP, like suggested by fiatluxia looks interesting, to start a campaign with Stick to the Plan and Ever Vigilant.
, who want to go Down the Rabbit Hole might consider that for the dualclass Spells Brand of Cthugha, Divination, Blur or Earthly Serenity. Taking three of these cards at deck creation effectively gives 6 XP, avoiding the penalty from DtRB to add them later. Not sure if that's worth it. Arcane Research nets likely more than DtRH for most and 4 traumata is a bit much.
Charisma (or for some Relic Hunter) is another solid pick, offsetting the traumata with additional soak options, keeping your allies or Holy Rosary longer in play on top of the additional value from whatever you play with it.
But the combo, I'm most eager to try out, is sending Nathaniel Cho into the rabbit hole. Thanks to this card, he can take Versatile at deck creation and then the Permanent. This is also true for any other investigator with any other of the new "Limit 1 per deck. Purchase at deck creation."-Permanents, they could not take otherwise. But NaCho in Wonderland seems like the most striking combo out of the bunch. He has a lot of events, he might be interested in upgrading. The same goes to Allies like Beat Cop and (to a lesser degree) Grete Wagner, his Boxing Gloves, Safeguard, possibly Backpack or Bandolier. Not all these cards will be great at level 0. You might take On the Hunt just for the rabbit, so your level 0 deck might be worse than without this setup. But I think, the XP acceleration should be worth it. It should be also OK to pay 4 XP for a Charisma or Keen Eye later in the campaign (in particular, if you want to upgrade Grete), or 7 for Stick to the Plan and 2 for Ever Vigilant. The later could also be purchased at deck creation for 1 XP, since Versatile costs only 2, but I think, a Mano a Mano (1) would be the better pick at that time.
