It will not overwrite effects that modify power or toughness (whether from a static ability, counters, or a resolved spell or ability), nor will it overwrite effects that set power and toughness which come into existence after the ability resolves
The card's lore (and value) only grew as a result, making it one of the rarest Pokmon cards ever made
Golgari insects was already a well-supported Commander archetype led by Grist, the Hunger Tide and Zask, Skittering Swarmlord, so Seedship Broodtender would be right at home in those decks
Slowpoke has the following attacks: Rest - 0 damageThis Pokmon is now Asleep
The rest of the sideboard for UR TiTi contains cards to fight Oath, Dredge, Storm, and Workshops
As long as you craft a slower deck devoid of Game Changers, two-card combos, mass land denial, and extra turn spells, most Commanders are fair game