the path of destiny

my lp 1600
opp lp 800

opp had the path of destiny FD

if my opp activate it in my turn who will toss coin 1st?
and
what will happen if the 1st result is -2k? (instant lose / wait the other player toss?)

all effects must resolve before the duel ends, you both must toss a coin regardless of the 1st result.

Both players toss a coin at the same time, so the results could be a draw, 1 player loses or both gain 2000 LP.

Even if one player would flip before the other, the Duel can not end while an effect is resolving. (Rule of Super Rejuvination vs Exodia as last card in deck)

If both players drop to 0, it's a Draw.