Slowbro needs a Bold Nature with Hidden Power Electic maybe to take care of Gyarados.
Jirachi should be Impish and have some EVs in HP, or at least Protect over Thunderbolt for recovery. Also you can always run Thunderpunch over it although I don't know which would be more powerful.
There are many Mixed Sweepers better than Honchcrow.
Try a Bulkier set on Gallade because its still quite slow even with 252 Speed EVs and a Jolly Nature. Also run Close Combat over Brick Break for the sheer power it packs.
Jirachi should be Impish and have some EVs in HP, or at least Protect over Thunderbolt for recovery. Also you can always run Thunderpunch over it although I don't know which would be more powerful.
There are many Mixed Sweepers better than Honchcrow.
Try a Bulkier set on Gallade because its still quite slow even with 252 Speed EVs and a Jolly Nature. Also run Close Combat over Brick Break for the sheer power it packs.