>Go onto Bulbapedia or Serebii or whatever Pokemon sites have a random page feature with all the pokemon.
>Go through random pages till you get a pokemon, then make a mega for it.
>Do this till you have a full team of megas.

Mega Dragonite
Dragon/Water
Multiscale
91/154/105/110/110/130
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Mega Floatzel
Water
Magic Guard/Swift Swim (can't decide)
85/120/85/85/80/140
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Mega Dusknoir
Ghost
Shadow Tag
45/200/85/65/85/145
--------------------------------
Mega Delcatty
Normal/Fairy
FurCoat
70/75/95/55/95/90
--------------------------------
Mega Granbull
Fairy
Strong Jaw
90/170/105/40/100/45
---------------------------------
Mega Jolteon
Electric
Lightning Rod
65/65/70/140/95/190