Cheapest priced copy (Battlebond): $0.49 at Card Kingdom, near mint, their price list as of .
Together Forever 
Enchantment · Rare · Teenage Mutant Ninja Turtles Eternal · #44
When this enchantment enters, support 2. (Put a +1/+1 counter on each of up to two target creatures.)
{1}: Choose target creature with a counter on it. When that creature dies this turn, return that card to its owner's hand.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
8 printings · $0.49 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battlebond | 32 | Rare | $0.49 | $3.99 |
| Commander 2020 | 105 | Rare | $0.49 | — |
| Commander 2021 | 108 | Rare | $0.49 | — |
| Final Fantasy Commander | 257 | Rare | $0.49 | $2.99 |
| March of the Machine Commander | 212 | Rare | $0.49 | — |
| New Capenna Commander | 212 | Rare | $0.49 | — |
| Teenage Mutant Ninja Turtles Eternal | 44 | Rare | $0.49 | $3.49 |
| Zendikar Rising Commander | 22 | Rare | $0.49 | — |
6 rulings from Wizards of the Coast
- 8 June 2018Together Forever's activated ability checks whether the target creature has a counter on it as the ability is activated and as the ability resolves. If the creature loses its counters later in the turn, the delayed triggered ability will still return it to its owner's hand when it dies.
- 8 June 2018You can't put more than one +1/+1 counter on any one target using the support action.
- 8 June 2018If a creature without counters receives enough -1/-1 counters to reduce its toughness to 0 or less, Together Forever's ability can't be activated before state-based actions put that creature into its owner's graveyard.
- 8 June 2018If some, but not all, targets for a spell become illegal, the remaining targets are affected as appropriate. If all of a spell's targets become illegal, that spell doesn't resolve.
- 8 June 2018Support can target a creature another player controls.
- 8 June 2018If a spell with support has other abilities that target creatures, those abilities and the support ability can target the same creature.