Riverkelp* 3

Creature - Beast
Whenever Riverkelp or another permanent is returned from a graveyard to play, draw a card.
Whenever a card is played from a graveyard, draw a card.
Persist
This looks like a new card made for Ichorid. It sacks and returns with Cabal Therapy due to persist, draws you a bunch of cards you can trade in for dredge. Unfortunately, I'm not fully aware of all the intricate game details of playing Ichorid. The question is, would you want to use your first dread return on this creature instead of others?
This card also does great with crucible of worlds, welder and yawgmoth's will, but I don't see the 5cc as a viable option in anything that doesn't cheat this thing into play.
This card doesn't really help ichorid at all because it has to be in play before ichorid's upkeep triggers resolve which implies that it was the target of dread return the previous turn. Cephalid sage is going to have a similar effect as riverkelp but as soon as it comes into play as opposed to the next turn.
Concerning yawgmoth's will: I think that if you've had the time to resolve will and other spell(s) in your main, excluding will, totaling 5 mana, you'd have won regardless of what you played. There are a lot of cards that are good with yawgmoth's will but are not good by themselves; riverkelp is one of them.