Whos the cat's pyjamas now
Basically, you grant the turns Energy to Feebas first, and then in the very next turn, you evolve into Milotic and use its ability and the turns Energy to give it all it needs to attack right away
Then, select the deck you want to personalize, and when editing that deck, go to More Details, to the right: Notice that sometimes you may miss and to the Sideboard (which is right above More Options), but what youre looking for is the screen shown below: Within a deck's details, you can set individual preferences for companions, sleeves and avatars for when you play that deck
The lack of haste means Mishra needs to live, but Phyrexian Dragon Engine has Unearth, so you can get that on the field from grave with haste, swing in, and get the meld