This is pretty good! Playtesting went well.

Cool deck, I am trying to find the best way to use heroic in standard and this is cool! Compare it to my deck: Heroic Boros Dudes (NEED SUGGESTIONS).

HEROIC IS THE BEST!

Endless One? Very simple drop that works with +1 counters.

I tend to prefer smaller effects that put counters on things one or two at a time because of Hardened Scales. For example, if I have Hardened Scales up and I play Endless One for 1 mana, he'd be a 2/2 - double my mana investment - but if I play him for 7, he'd be an 8/8. As I pay more into him, he gets less efficient because Hardened Scales only gives me one more counter for each time I put counters on something. Meanwhile, Hangarback Walker would be getting two counters every turn for 1 mana each time.

Endless One is impressive, but he's better suited to a deck that ramps mana than Hardened Scales. I want to play a creature small and then watch them grow insanely powerful through efficient, small effects.

I run a similar build, but with less enchantments. You should not be running Collected Company you will miss quite a bit. In order to make collected company worth it you need to run at least 22 creatures.