Sunburst isn't a good ability. I know there'll be some people who'll defend Sunburst to the nth degree, but there are so few sunburst cards that are worth the investment and effort.

One thing I'd like to rationalize is the more colours you need, the harder it becomes. This should be obvious, but some people I know don't think so.

Imagine there was a WhiteBlueBlackRedGreen2 0/0 creature that came into play with 5 +1/+1 counters and had Tap: Double the amount of counters on it. Would you think that to be a good creature? Of course you could abuse the counters, but you need to usually wait a turn before that happens. Personally, I'd think it to be an over-costed creature that is rather slow.
This is Solarion.

Imagine another creature that was a WhiteBlueBlackRedGreen4-cost 3/3 that came into play with 5 +1/+1 counters and had "4Tap, remove a counter from this: destroy a creature" and "2, remove a counter: return this to your hand". I'd say it's overcosted as well, and multiple other c... (see all)