When I cast a spell using another player's Charge ability, who discards for Starfire Frenzy's bonus?

Question

Accepted Answer

The player using the Charge ability, since that player is the caster. The bonuses stack: base damage, discard bonus, breach bonus and the ability's own extra damage.

Aeon's End: Legacy

When I cast a spell using another player's Charge ability, who discards for Starfire Frenzy's bonus?