Okay not sure if this has been discovered however people use it for chain grabbing and have entirely overlooked its potential. the attack is "grab with popo then short hop with nana (press x/y) then use fair and nana will spike the opponent or knock them pretty far. can be done with fair or bair (for bair do the same thg except push opposite way slightly before doing fair) 20 damage for fair 18 for bair and is very good against Marth 
