You're welcome!

If it was me doing this, this would be the design:

[Partner's Name] / [Your Name]

Cost: 0 [Colourless]

Legendary Creature - Angel

Set Symbol: [Heart Shape]

Rarity: [Mythic]

Flying

At the start of each game, if there are exactly two permanents named [Partner's Name] and [Your Name] in your deck, the "legend rule" doesn't apply to them.

When both permanents are on the battlefield, they gain hexproof and indestructible at the beginning of each player's turn.

This card and its abilities can not be copied.

0.5/0.5

Set Numbers: 1/2 & 2/2

Note: I don't know of any cards with 0.5/0.5, but the idea is that, together, they make 1/1, making them useless unless they attack together.