Heart of the what? In Pledge decks, Alhed is a better choice. Much easier to cast, has an activated and ongoing inspire ability, and same stats. One problem with current Praxis/Pledge decks is that they have trouble dealing with opponents large troops. With Alhed, the opponent will have to deal with your much larger troops instead.
T1> Initiate
T2> Merchant - grab Alhed
T3> Drop Alhed
Now have fun drawing units from deck, and with Reliquary and Moonstone, or from playing Glasshoppers.
NOTES
- Alhed + Cykalis >> When Alhed is in play and you draw Cykalis from the deck or a Glasshopper, it will hit the board at 10/4 with Charge/Invulnerable/Overwhelm. After attacking with Cykalis, use Alhed to put Cykalis back on top of the deck and now Alhed is 16/10. When you draw Cykalis, he becomes a 20/8 Charge/Invulnerable/Overwhelming game ender. And if you happened to have 2 Alheds in play when drawing Cykalis.... may god forgive you. Heart of the what?