Some good design decisions here. I think it's important that using the happiness counter ability doesn't inherently trigger the first ability. From a balance perspective, this would be fine in multiplayer, but it feels a bit too pushed for constructed. 4 toughness is a lot, as it dodges Lightning Bolt, and it super punishes burn decks that run out of gas. This is strictly better than Those Who Serve, which is fine at a higher rarity, but it feels like it's just a smidge too strong. I might have made it a 1/4 or a 2/3, or had it cost .

The idea of stockpiling happiness for later use originally sounded weird to me, but I think it's actually kind of cute. I just have this idea in my head of a guy who concocts drafts of happiness and gives them to people to save for times of difficulty. Sounds pretty great.

I think this gets there for a 1 point totem, but it might not have made the cut for a totem worth more than that.

+1/+1 counters are ubiquitous enough to be found in any color, and the Ring cycle suggest this kind of effect can be allowed to exist. Most of the cards here aren't poorly designed, but the last two aren't very interesting either. The flavor text on Animated Bookshelf is super not blue.

Very interesting card to build around. You can exile something inexpensive like a Ponder and get something totally random. Likely to benefit you more than opponents. And then that instant/sorcery is cached with Sut'zhuki, meaning if you randomly pick that one in the future you effectively get to try again (unless you really want that Ponder). Feels like she could be a super fun card.

There are a number of things you may not have considered here. If you exile all instants and sorceries, you can get infinite storm count with her. Which is fine if that's what you meant, but still. If it wasn't, it may have been better to do this as a triggered ability. The more glaring bit is that if she's your commander, casting her multiple times doesn't give you access to the full breadth of cards she's exiled over the course of the game. That may have been your intention, but I think something similar to how Karn, Scion of Urza functions would have been cool here.

The flavor text doesn't feel very distinctive, which feels kind of like a miss.

I like this card a lot, but I think there were a few too many misses for it to pass on a 7-point totem.