Since youre gaining life while your opponents are losing life, Gray Merchant lets you pick and choose which of Astarions abilities you want to trigger at the end of your turn, either putting your opponents in a precarious situation, or helping you take the lead with a massive surge of health
If anything, it churns away and makes it deep into games if only because it's the lowest threat at the table and gets treated as such
Mind's Eye : Draw whenever an opponent does for 1 mana
And mechanically speaking, that shows up beautifully here as his static ability doubles all damage he would deal, and at the beginning of each end step, if he dealt damage to another Creature that turn, he gets a +1/+1 counter
Glimmervoid Basin Glimmervoid Basin allows players to copy an instant or sorcery similar to the effect of Zada, Hedron Grinder, except it targets every single possible target