In conjunction with Naban, Dean of Iteration, it can be incredibly powerful by stealing the opponent's two best creatures, although something like a Lightning Bolt, Path to Exile, or Fatal Push undoes all of our work by giving the creatures back
Venat, Heart of Hydaelyn / Hydaelyn, the Mothercrystal In Final Fantasy XIV , Venat becomes Hydaelyn, the crystal embodiment of lightand Venat, Heart of Hydaelyn reflects that in Magic
Maarika forces your opponent, and no one likes being forced
Tamiyo is fine, I stand by my initial review of her and think she is the third best 5 mana walker and likely to be in the top 10 of all walkers
Yes, you need a token, enchantment, or artifact to sacrifice, but that can happen incidentally during normal play