So this card is... not very impressive. I can see it's use with cards like Pemmin's Aura and Jeskai Ascendancy, even then it'd take a 2+ casts before it's advantage takes root; per turn. However, I guess that's what makes building his deck enticing.
Good thing about Gnostro is that it's not limited to non-creature spells like many other Jeskai cards. If you add Eligeth, Crossroads Augur you get to draw the cards you scry, or use Scroll Rack to put useless stuff on top of your library then scry them away. If you want to deal damage directly to opponents, Brash Taunter, Stuffy Doll, and Repercussion are your friends. A typical combo (?) would likely be cast 3ish spells, then continue to tap/untap Gnostro to deal damage to Brash Taunter for direct damage. In this scenario, Blasphemous Act becomes a direct 13 damage hit as well.
To maximize Gnostro's power, cards that untap lands like Frantic Search and Time Spiral let you play more spells, and flashback/jumpstart let you cast those spells again, Jace, Vryn's Prodigy and Chandra, Acolyte of Flame let you play the rest.
Can we find other tricks to pull this Chimera out of the swamp?