Great suggestions, thank you!
I don't currently have a
Halo Fountain, but I actually like this suggestion best since it really can do a lot of work without being a win-con. I didn't like the card when it was first spoiled, since I'm not usually such a fan of explicit "win the game" effects, but I don't think I realized its utility outside of that before.
I'm at least going to stick in
Walking Ballista though, as it can also be a mana sink even if I don't have Heliod out.
I'm hesitant about Reservoir though, since the lifegain in the deck isn't the strongest, and I often get stuck topdecking lands after too long while goldfishing, so I don't even have a lot of spells to feed it.
Thank you! And I'll see if I can
acquire a
Halo Fountain to stick in there too!