0124 Jynx

Confusion has a very nice stat line, providing above average damage with solid energy production. Frost Breath has inferior stats, but provides Ice-type coverage. 

Avalanche is a very strong move with great coverage and reasonable energy cost, making it a must have for dealing with many of the Pokemon that Jynx wants to counter. Psyshock is a cheap and relatively strong move that enjoys STAB, though Ice Punch's lower energy cost also makes it attractive despite the fact that it shares the same type as Avalanche.

Jynx hits hard and has decent coverage, but that's about it. It's far too frail to be considered a good general pick, and it's too slow to be a solid glass cannon like Haunter. Ice and Psychic typing generally doesn't synergize well, with a big list of weaknesses and no worthy resistances to really make up for it. 

Jynx generally has more favorable matchups in this league due to additional stats that enable it to stay on the field longer. Ice Punch is generally recommended for this league due to its lesser energy needs to keep up against its opponents, despite being limited to Elite TMs. However due to its unimpressive overall performance, this may not be worth that cost, and it's probably better to choose other Pokemon rather than Jynx. 

Jynx is a liability in the Master League.