If you casted only 1 Spikeridged Steed in the game that's already a good card. Any other buff you cast makes this card better. The problem is that if you don't draw Spikeridged Steed before this it's a bit awful. Idk how to evaluate this. Also I'm pretty sure that this doesn't make paladin's quest viable.
If Paladin gets one more Steed-level buff card then this goes from too inconsistent (you need to draw and PLAY Steed before this card is even live) to potentially just an exceptional 7-drop. It all comes down to what new buff spells Paladin gets because the current retinue simply is not enough to validate including this card.
If you play a deck with 2 x BOK and 2 X Spikeridge this card could be very powerful. Everyone says, "well it's a silence magnet." But that presumes your opponent didn't cast silence already on an earlier, buffed minion. They can't cast silence over and over (I hope), so by the time you get to this card it could be a massive problem for your opponent. Anyway, I am eager to try it out.