That's fair enough, though Efreet is still retained as a separate type to flavour more 'evil' djinns, which is true to their mythological basis
Check out the transforming Gwen Stacy/Ghost-Spider card
For the most part, if your deck competes with a preconstructed deck out of the box, but does not overpower it, chances are that your deck is a Tier 2 deck
An Aura put onto the battlefield this way can enchant an artifact, land, or creature that was already put onto the battlefield, but can't enchant an enchantment that's being put onto the battlefield at the same time as it
And lo and behold, it made it into the set
Grumgullys ability nullifies this due to the +1/+1 counter it gives, which means all you need is a sac outlet for infinites