You Live Only Because I Will It is not legal in any format.
Rulings
2024-09-20
In a game with shared life totals (such as a game of Commander Archenemy), each team has a single life total.
2024-09-20
When life totals are redistributed, each player gains or loses the amount of life necessary to equal the other player's life total. For example, if one player has 10 life and the other has 17 life, the first player gains 7 life and the other one loses 7 life. Replacement effects may modify these gains and losses, and triggered abilities may trigger on them.
2024-09-20
You choose which player or team gets which life total when the ability resolves.