While the design and the flavor of that card is great, it is sadly underpowered imo. I've run it in a dedicated Luke deck with plenty of static book boost (magnifying glasses, st Hubert key, yellow tarrot card), enablers and even then, at most, the summon picked up three to four clues over the course of the scenario, even fully upgraded. Sure, sometimes, it came handy because it evaded a few monsters for my fellow investigators, but if you had to choose between that card and Powerword, the latter is far more useful and versatile, and doesn't require a build around deck to function (even if the comparison is unfair, since a fully upgraded Powerword is the most absurd card in the game).
You clearly don't run it for the extra bit of unreliable damage, but mostly for its evade and investigation ability (also its 3 health pool that counter balance the squishyness of most mystic investigators). It's also awkward to use since it cannot explore on its own, and can only navigate through explored areas. Most of the time, I just landed it on a location I was tasked to investigate, then joined the rest of my team while it picked some clues on its own. The best point of this card is it offers you a good presence across the board, no matter your location (your own dream world for exemple). I absolutely recommend it if you want to do a Luke run. It's really a lot fun to watch the little buddy lives its life to its fullest on its own but you should rather skip it if you plan to play anybody else.
The card would've been great if it wasn't considered "unique" and you had to fantasy to be able to run two of them at the same time. In its current state, it is a below-average/okay card in a dedicated deck, but it won't carry you your investigator on its own. It kinda fits a peculiar archetype (flexing) as an element of the whole, but not at the foundation of the archetype. The ability to go through uncharted locations would make the card far better than it is now, even if the owner of the summon would have to be hurt the revelation ability from those locations. Putting two extra xp as fee with a taboo on "Wings of Night" with this said ability would solve a lot of its problem, without hurting the balance of that card.
Here is the list I used for a return to Dunwich playthrough:
Initial version: arkhamdb.com
Fully upgraded: arkhamdb.com