but it's also because he's a meany of a card.
unless i'm wrong, i believe he swings for 4500 (or 3500, i forgets), and can clear either monsters, s/t or reset ntp's graveyard.
and as a tip to OP, in a deck i'm trying to make, you can fuse rainbow neos in 4 cards:
1. giant trunade/heavy storm (to be safe)
2. reinforcement of the army/e - emergency call => elemental hero prisma
2b. summon prisma and use its effect to reveal rainbow neos. send either rainbow dragon or dark rainbow from deck to grave.
3. e - emergency call to neos
4. polymerization
another option for 3 is (but longer.
alt 3. foolish burial => neos
alt 4. o - oversoul/swing of memories => neos
5. poly
or i guess, future fusion.
then o-oversoul/swing of memories => neos to field,
monster reincarnation the dragon to hand
and poly for 2 rainbow neosessssss