Expected Behaviour:
Using OpenDNS as the upstream DNS provider, I'm expecting it to use an existing OpenDNS account's settings to continue the same blocking parameters.
Actual Behaviour:
It's defaulting to a standard OpenDNS ruleset.
Debug Token:
https://tricorder.pi-hole.net/pgvrjmlten
So, to further explain - the network I've installed the Pi-Hole on already had OpenDNS running for years, custom block page, custom ruleset, the works. However, now that .222 and .220 are the upstream for Pi-Hole, ODNS is returning block pages for it's default rules, which only appear to protect against purely malicious sites; the previous ruleset blocked pornographic sites and most foreign domains.
How do I have Pi-Hole point to these settings?
I'm not familiar with OpenDNS myself, but our docs do have some information on using it as an Upstream DNS Provider, mentioning standard and FamilyShield options, which may just be what you are looking for.
I do have it as my upstream, but the specific rules are what we want to use (for example, FamilyShield does nothing for the foreign domains). Will try asking the OpenDNS crowd as well.
On an unrelated note, how do I view what clients I have? Based on the dashboard I fluctuate between 2 and 7; first I have no idea why that's fluctuating and second, when I go to Group Management>Clients, all I can find is a drop down that appears to list every device that ever connected, as opposed to what is connected.
Use "Network" to get an overview over your network/clients that use pihole.
Yes, OpenDNS is likely a better source for your issue.
From your description of tailored indiviual blocklist rules, OpenDNS has to somehow associate a DNS query to those individual preferences of yours, and since this is not part of the DNS protocol, it will be a solution specific for OpenDNS.
I'd have no idea how they actually achieve that.
If they'd do it on their servers based on your known public IP addresses, queries arriving at OpenDNS via IPv6 could pose a problem: While all devices in your network share your router's single public IPv4, they may each have a separate public IPv6 address, notably different from your router's IPv6.
If they do it by some client-side magic on your router or some other device, you'd have to forward DNS from Pi-hole to that device.
So you are correct:
As this is not a direct Pi-hole issue, OpenDNS should be able to point you in the right direction. 
Thank you. On a more topical point; going through the network log linked by yubiuser, I'm noticing the vast bulk of my requests are only coming through my gateway...but some ARE coming from individual devices. I also have most devices not seen in the last 24 hours....including the device I'm using to read the admin console. Which I checked with a known blocked site; it's connected to the pi-hole, but the request is logged to the gateway. And there's a half-dozen or so devices marked as not using Pi-Hole. And yesterday I had seven devices connected according to the console's dashboard (a more appropriate number) vs. 2 today.
My router's pointed to the Pi-Hole for DHCP, so why is everything seemingly being funneled to the router for requests?
Depending on your router's lease time, it may take a while before your devices will request a new IP address via Pi-hole's DHCP (e.g. my router would issue leases valid for ten days by default).
If you don't want to wait until lease expiration, you may force your clients to renew leases by disconnecting and reconnecting them to your network, either by turning WiFi on and off or by restarting or powercycling a device.
Just to follow up - it turns out the issue was unrelated to pihole; the device hosting the DNS account credentials had misconfigured and was no longer synced to OpenDNS - thus when ODNS received requests from the pi-hole, it was finding no valid account to pair them to and fell back on its default settings.
Thank you for the assistance nonetheless.