Many times these new mechanics wont work very well with the existing card frame
However, this creature has a drawback, receiving -X/-X where X is your life total
Cast this turn one, swing turn two, ting the defender, toss a +1/+1 counter here with your mana, you've now dealt three with your 2/3
Granted, Assault on Osgiliath requires you to be playing Goblins, but its not like thats strange to build around these days, so I consider this one of those silver-bullet theme cards
If you do get it out early, it does a lot for not a huge investment
This is possible by using certain combinations of cards.) Technically speaking if a non-mana ability of a land produces mana like this, the ability of Caged Sun will trigger and it will not be a mana ability in this case according to the strict interpretation of the rules (and thus will use the stack.) In other words, whether the ability of Caged Sun is a mana ability or not depends on what's triggering it