Glissa's card also was serviceable but ultimately not great, yet she got a second chance at glory thanks to Glissa, the Traitor
Forerunners is significantly better than Decimator, being cheaper to cast without having to sacrifice creatures and adding a sweet bonus vigilance to the mix, which means that even if your attack doesn't win you the game you still have blockers to protect against any crackbacks
This particular one is a 'what if' scenario where Arthur from 1963's Sword in the Stone becomes a spellcaster in his own right
The aftermarket is always an option, although it tends to come with an uptick in price
Gemstone Mine has come back as recently as Time Spiral, but its a confusing enough card that I doubt well see it again soon
Flamewake is already preordering for around $5, which isnt far from the ceiling on a card like this