If it werent for the mana engine, Vivi might not be as terrifying, but the fact that he provides a huge source of resources for free on his turn makes him one of, if not the best Commander in the game
Like Timmy, Power Gamer and Johnny, Combo Player before her, Spike is a 4-mana 1/1 with a game-breaking activated ability
The problem with the card is that you really need to build around it to make it work for you however there is not enough redundancy in the effect to make that reliable enough
This will get you the cheapest price possible while allowing you to make changes and save money on cards you wouldnt play anyway, which is a win-win in my book
Making each other land (including your opponents') swamps instantly fixes your mana and makes your Caged Suns and Crypt Ghasts sing
In this limited season, you will see plenty of familiar cards unless you are a completely new player