This is great, as Warren Warleader can build a good board the turn it comes down, plus you dont need to ever attack with the 1/1 offspring either
The planeswalker deck version Nicol Bolas, the Deceiver is the only version of Bolas that looks a little on the weak side, but for the sake of completeness for Bolas tribal, I think its fine to take a slot for it
The activation cost is unaffected if it already costs one or zero mana (such as the activation cost of Zirda's last ability)
Among this you will find Pokemon such as Bellsprout, Accelgor, Leafeon, Clefairy, and Slakoth
Honorable Mention #1 - Experiment Kraj Experiment Kraj is a fun card, and one of only a handful that will copy abilities from others
Coming down a turn earlier than Ranger of Eos is such a big upgrade, and the sacrifice ability buying you a turn against combo decks or decks with Supreme Verdict is huge