The value of X won't change even if the number of lands you control changes after that point
If you're worried about a board wipe like Ritual of Soot, Tend the Pests only gives you 1/1s, but A: that's more than enough damage to kill every player at the table many times over, and B: They gain you life when they die
But at the same time, I'm a longtime advocate or aficionado of six mana Akroma's Vengeance-types
If you do, at the beginning of the first upkeep, your life total becomes 26.Your life total becomes 26
You still see it from time to time, usually in a newer players deck, but if the right knight cards come along I could see a resurgence for this quick 1-drop
Im considering all the different Edge of Eternities -related sets: Edge of Eternities (EOE) This is the main Standard set, and you can get these cards in your Play booster or Collector boosters