Combined with owyn, he can be incredibly absurd, as youll end up tapping down several creatures every single turn and wreak havoc with your army of humans
Speaking of boxes, if you do want to buy a lot of packs I included some above as reference, you usually get a way better deal if you buy a booster box instead

Ancestral Recall Arcum's Astrolabe Balance Bazaar of Baghdad Black Lotus Candelabra of Tawnos Channel Chaos Orb Deathrite Shaman Demonic Consultation Demonic Tutor Dig Through Time Dreadhorde Arcanist Earthcraft Entomb Falling Star Fastbond Flash Frantic Search Gitaxian Probe Goblin Recruiter Grief Gush Hermit Druid Imperial Seal Library of Alexandria Lurrus of the Dream-Den Mana Crypt Mana Drain Mana Vault Memory Jar Mental Misstep Mind Twist Mind's Desire Mishra's Workshop Mox Emerald Mox Jet Mox Pearl Mox Ruby Mox Sapphire Mystical Tutor Nadu, Winged Wisdom Necropotence Oath of Druids Oko, Thief of Crowns Psychic Frog Ragavan, Nimble Pilferer Sensei's Divining Top Shahrazad Skullclamp Sol Ring Sowing Mycospawn Strip Mine Survival of the Fittest Time Vault Time Walk Timetwister Tinker Tolarian Academy Treasure Cruise Troll of Khazad-dm Undercity Informer Underworld Breach Vampiric Tutor Vexing Bauble Wheel of Fortune Windfall Wrenn and Six Yawgmoth's Bargain Yawgmoth's Will Zirda, the Dawnwaker Who is Legacy For

That sounds good
Borderless Panel cards, Web-slinger frames, Classic Comic, Scene cards, and more
Silver-Fur Master grants so many options on its own, and it can turn an already-good ninjutsu deck into a near-unbeatable ninjutsu deck (so long as the draws are good, of course)