Greenawisps

You're definitely right that the Smuggler/site package is really strong, it seems like a good core to build around. You don't even need wisps to use it, but I think they're one of if not the best options for the shell. The main problem with the smuggler/site plan is it can't really finish the game a lot of the time since you have to trade a lot to survive. You can survive really well, and the trades are generally slightly positive so you'll end up a little ahead. But there's not a whole lot to really "turn the corner" with. So you end up taking a long time to win, giving them enough beat you sometimes. The wisps give you a unit base that basically scales infinitely through slightly positive trades. So instead of surviving the onslaught and then trying to hit them with a 2/2 every turn until they die, you survive and end up with a board full of badass wisps when they have nothing.

I think Wisp decks have a bit of learning curve compared to some other decks. So if you haven't played them a bit before they can seem lame. All of the units in the deck are pretty bad stats-wise so you have to build them up with all the recursion. This means playing the deck involves thinking and planning through a lot of mechanical interactions, and most of them are pretty unique (in both Eternal and in other card games) so you're less likely to have practice. A lot of the good plays seem kind of bad on their face because other decks don't usually build up value like this one does. Things like having a unit with Killer in the void or having a Weary Spiteling die can actually be really valuable for this deck, whereas normally they wouldn't really matter.

I'm not saying I'm an expert or anything (these might all be obvious to you), but here are some things I think are important for playing this deck:

- Generally you're trying to buff up units then recur them. This generates value because you're recurring the unit itself as well as the buff. So ideally you should avoid bringing back Wisps until they're enhanced somehow. This isn't always possible, a lot of times it's definitely best to play Shadowlands Guide to get a 1/1 Pathlighter. But if you can wait for a Tribute Pathlighter, something with Killer, Weary Spiteling, or even just a Soulbringer buffed Wisp then it'll generate more value, and that's how you win games. Entrancer can also be good to bring back as it permanently weakens your opponent's cards so that's a kind of scaling value. It can miss and give you no value so be careful, but silencing 2-3 units from the enemy hand is really strong.

- Usually it's bad to play Xenan Initiation on a unit then trade it with an enemy unit because that's a 2-for-1. But if you bring that unit back with Shadowlands Guide/Soulbringer then kill something, that's a good trade (on it's own). You just played a decent unit with a removal spell attached, so that at least makes up for the earlier 2-for-1. And if you get something extra out of the killer unit (e.g. Tribute, or an Entrancer proc), it's actually pretty strong. Then you can do it again (and again, and again...), and it just gets better each time. This is how you win a lot of games. Having a 1 drop/Wisp with Killer is very strong for this reason, they're the easiest to recur. So don't be too afraid to 2-for-1 yourself if it means you get a Wisp with Killer (ideally not Entrancer, although that's still fine).

- Dark Return is very useful because the deck can make a lot of really good 1 drops, so it's usually easy to play a good unit from the void for cheap. But IMO its real strength is in bringing back Shadowlands Guide and Soulbringer to get that double return action, so you should try to hold on to it for those. A very strong play is to give Soulbringer Killer, trade it for something, then Dark Return and play it with Tribute and another Killer attack. Also remember Xenan Temple steals enemy units so sometimes it's best to just kill their Vara or whatever so you can Dark Return it and win with that.

- The sites are really strong but you don't always want them. You can win a lot of games more quickly/reliably with just Stand Together. I used to almost never get it but my winrate definitely went up after I started grabbing it more often. Generally I'll get it if I have a good board, and I either don't think I can protect a Site or I don't need to play one to win. The sites are great but they're slow and have a lot of room for counterplay. So a lot of the time Stand Together can save you or slam the door shut on people better than any Site.