Medivh the Guardian is good substitution.
With Barnes? Not good.
With empty hand? Not good.
With 14 minions in our deck? Not good.
With 10 spells with cost: 0-3? Weak.
But..
With Astral Communion and empty hand? Looks good.
With 2x Nourish and 2x Moonglade Portal? Very good.

Barnes summon Naga. When?

1st -> Barnes in 4th turn, in 5th turn U can play a big minion.
2nd -> before 9th* turn: U can play Barnes as the last.
3rd -> after 9th* turn: U can play Barnes as first.

*with Innervate 7th turn, or 2x Innervate 5th turn.

This is a classic deck, always in standard.
U can add the currently played cards.

OMG. Sorry.. [Edit]