In the case of Ugins Conjurant, youre looking at a free dies trigger, a free cast trigger, and maybe an extremely unlikely place for a tribal Spirits build to dump a whole bunch of mana
This four-mana mono-green 4/3 makes every creature spell you cast with power 4 or greater cost two generic mana less, and whenever she attacks, each of those big creatures gets +1/+1 and trample until end of turn
Does what it says it does, unlikely to be game changing, but certainly something you need to deal with
Imperious Perfect, Leaf-Crowned Visionary, Canopy Tactician, and Elvish Clancaller are popular creature cards that provide anthem effect for elves, which can steadily elevate Glistener Elfs power for more infect damage
Given that Water-type decks are very popular in PvP battles right now, this is something you could consider trying