Note the lack of "1/turn" or "exhaust itself"...so you can dump into it multiple times in a turn. Great to combo "hand dumping" with Mulligan. Also the same if your entire team is playing it (unique) and the next person wants to start using the same trick. :)

This feels like a very underrated card with some decent non-pool allies. It costs 0 to get out and then can be used to heal up to 7 at your leisure.

At its cheapest, this is 4 ER to heal 3 and deal 3 damage. That alone would be a great value. At its most expensive, it's 8 ER to heal 7 and deal 7 damage. And this can be split up across several turns, used to make a basic ally effectively immune to consequential damage for up to 7 turns and then slap an enemy in the face with all of that damage.

So what are some good allies to use with Tic-Tac-Toe? What basic allies get the most out of being healed by Tic-Tac-Toe?

Snowguard can either have 3 thwart or 3 attack. Either of which dramatically increases the value of Tic-Tac-Toe.

Gambit is a bit more conditional, but can potentially end up with 3 attack and thwart. If he does, he's worth keeping around with this.

Storm is considered to have 4 effective thwart, letting you shuffle threat from one bad scheme to a less bad one.

Gamora in a Guardians of the Galaxy deck might be the best use of this, letting you put an event in your hand and making the cost effectively free.

Rocket Raccoon can just straight up massacre minions with 4 attack and overkill. And his 2 thwart wouldn't be a terrible use for this on turns with no minions out.

You can also get more value out of any of the attackers by equipping a Sidearm

Also consider heroes that allow you to mix aspects. Spider-Woman and Adam Warlock can make great use of this with non-basic allies. And it's great in multiplayer where you can heal the allies of teammates.

The weirdest thing about this card is just that the thing it's best at is negating consequential damage in an aspect that doesn't have consequential damage. It's a Pool card that's ideal for non-pool allies.

Edit: Someone asked how to get 7 damage out of this. Go for this pattern:

OXX

XOX

XXO

The final square you fill in will be your seventh damage.

Multiplayer Perspective: This is one of the Staples from the Pool Aspect and functions similarly to Med-Team. If you have a high-priority ally: Voltron Strategy, Signature Ally (Captain Marvel), etc... the value skyrockets. The max activations you can get out of it is 6 (Physical, Mental, Energy, Mental, Physical, Final Point Anywhere) That's 6 more activations on a non-permanent Voltron Target, 6 more draws off of Captain Marvel, and up to 12 Damage/Thwart on average (18 damage when counting damage from Tic-Tac-Toe itself). All of this packaged in a zero-cost upgrade that can sit around till you have a dead card at end of turn. The major downside of this card is that playing the Pool Aspect typically eliminates your access to desirable allies. For that reason I would recommend playing this in a multi-aspect deck (Spiderwoman) or a hero with access to strong/plentiful basic allies (Guardians/Web-Warriors/X-Men). Imagine keeping Storm on board for 9 turns with her effective 4 Thwart.