Great Tome is a legendary major card out of the New mechanic pool. Tome Pulse is a 6.5 u pulse at 75% damage on a 20% longer cooldown.

You can take it once · it only turns up when your Special ability can actually use it · it can be offered for 0 of the 34 abilities.

Only one card can reshape that ability this way — this one, or Twin Tome and Smouldering Tome. Take one and the rest are gone for the run.