hmm, 6 reapers 1 bone dragon, kill the bone dragon => 6 more powerful bone dragons for 1/2 the cost. and thats the nice version. what about growing or blessed cratures in a rainbow deck? 2 or 3 of this card would be the ultimate protection for them.
what happens, if a reaper dies due to fire shield or thorn carapace and there is another reaper on the field (base value is 0|3 ?)? what happens, if a creature died through poisoning? what happens, if your opponent plays a spark? what happens, if multiple creatures are dying simultaneously? (although the will probably die from "left to right")
i think, the cost should be raised to 7 
or 9 , to be in line with twin universe | mirror universe costs. other than that, the idea is great.
Yes, base value is 0|3, but if a reaper dies while it has the attack of a different creature, the second reaper will gain that attack, and 1 hp, since the only way the reaper can die is from poison or fire buckler and will have 1 hp the moment before it dies.
If a reaper dies from fire buckler or by poison, then the attack gets added to the second reaper and only 1 hp, since the hp before the creature died was 1.
Same goes for any creature that died in a similar manner. The Reaper gains the Attack and the HP that the creature had right before it died.
Spark gives the attack, but since it has 0 hp, Reaper doesn't gain any hp and remains at 3.
if multiple creatures die, the very last one to die will be the creature that affects the Reaper, since it was the most recent death.
