Shes not Ajanis Pridemate, but she can be just as annoying under the right circumstances
Even though its convoke cost means it's a little harder to pull off if you're already going wide with a full board of creatures, being able to flash it into play at any moment can come in clutch during board wipes or if you need to keep a commander alive for another round
If so, Runic Armasaur already becomes an excellent source of card advantage that needs to be dealt with immediately or you sort of run away with the game
Shift: Pay the cost listed next to Shift to play this card on top of a card with the same name
Now, the cost of doing it isnt small -- having to have another untapped creature isnt a guarantee, but if you are at parity or ahead of your opponent, it wont be that hard to make it happen
I know that getting mana from attacks is dodgy and you probably dont really need it anyway if you have enough mana for a 6-drop like this