Changelings OP/Advice is welcome
Amoeboid Changeling can tap to help defend your creatures by making them share a type with Knight Exemplar or Lord of the Unreal, this gives them either hexproof or indestructable as well as buffing them. It can also turn enemies creatures into reflections to trigger with Spirit Mirror. If you've had to cast Call to the Kindred on a non changeling creature then this can also be used to make it a changeling during the upkeep trigger.
Griffin Rider easily becomes a 4/4 flying due to the changelings and triggers with Knight Exemplar for +1/+1 and indestructable.
Call to the Kindred When attached to a changeling you can use this to cheat out any bomb that you want, I currently am using Progenitus and Worldspine Wurm. It also allows you to cheat out any other creature you happen to go past and can be attached to non changelings and reflection tokens to bring out Changelings. This combo is insane.
Shapesharer Act's as another changeling trigger and can also copy enemy bombs as well as having great utility in your own changeling shenanigans.
Peer Pressure Can steal your enemies creatures extremely easily, especially when combined with Shapesharer, Amoeboid Changeling or Shields of Velis Vel
Shields of Velis Vel extends protection to all your own creatures or allows you to setup against the enemy with Peer Pressure as well as comboing with Spirit Mirror to boardwipe.
Lord of the Unreal and Knight Exemplar act as protection.
Can easily be made into a budget by replacing the bombs with cheaper ones, Changeling Titan is a good choice otherwise you can put in anything you want