Before I continue, let me clarify that I'm not suggesting R&D made a poor choicebloodrush was a late addition to Gatecrash design and Return to Ravnica was most likely already locked in by that time (or at least too far along for such a large overhaul)
The companion mechanic first appeared in Ikoria: Lair of Behemoths , an expansion set on a rugged plane full of fearsome beasts
20+ Lands Wait, you're serious
There are also two digital-only Alchemy creatures with convoke: Buxton, Decorated Host and Emmara, Voice of the Conclave
This problem will naturally go away if you play with a regular group and they can see what you're up to, but if you're playing a game with strangers, they will probably assume you're playing a cutthroat Zur list unless you can prove otherwise
When Ao dies, choose one Look at the top seven cards of your library