Haha yeah. I'm still beta testing this VGC team. I love it on paper but it just has a glaring ice/fire weakness.
Yeah, personally, I would just have it with a Calm Nature and burn any physical attackers on the field.
252 SpA Chandelure Energy Ball vs. 252 HP / 216+ SpD Rotom-W: 152-180 (50 - 59.2%) -- guaranteed 2HKO
Timid 252 SpA Hydreigon Draco Meteor vs. 252 HP / 216+ SpD Rotom-W: 147-174 (48.3 - 57.2%) 252 SpA Mega Charizard Y Solar Beam vs. 252 HP / 216+ SpD Rotom-W: 214-254 (70.3 - 83.5%) -- guaranteed 2HKO 24 SpA Rotom-W Thunderbolt vs. 4 HP / 0 SpD Mega Charizard Y: 186-218 (62.4 - 73.1%) -- guaranteed 2HKO
12 evs in speed are there to speed creep other rotom-w. 252 SpA Rotom-W Thunderbolt vs. 252 HP / 216+ SpD Rotom-W: 90-106 (29.6 - 34.8%) -- 11.8% chance to 3HKO