Gyre Sage Ive always considered Gyre Sage one of the biggest payoffs for playing a dedicated +1/+1 counters strategy because it pumps out so much mana
The issue is that, even in a deck containing only land cards, if you start with a single land in hand you need to go nearly 20 cards into your deck to find that fatal damage
(2/1) Go for the Esper 3U Sorcery Create a 3/3 blue Robot artifact creature token
Even still, it's a worthy inclusion to the deck, especially as these tokens have extra utility in pinging players if they are tapped, either through attacking or another way, like crewing a vehicle
Mardu Roughrider, Mardu Heart-Piercer, and Bellowing Saddlebrute are the only nonrare creatures in red, white, or black I could consider taking over lands or removal spells