I think Half Bloods are potentially more fun to grind than Elders, due to the fact that they pose a bit of a challenge without upgraded or rare cards. There seems to be a focus on fast grinding decks, but those probably aren't fun for everyone to use (although I'm sure they were fun to make!) I'm trying to make a cheap deck that's fun to grind with - that is, without rares or upgraded cards. A winning percentage of about 60-70% is probably the sweet spot in terms of fun (though I'm sure it depends on your mood.) It's also more fun if a deck is less straightforward to use and requires more thinking, but again that depends on the individual. I've been messing around with the trainer, and here's what I have so far:
Hover over cards for details, click for permalink
5um 5um 5um 5um 5um 5um 5uq 5uq 5ut 5ut 5ut 5ut 5ut 5ut 622 622 622 622 63a 63a 63a 63a 63a 63a 63a 63a 63a 63a 63a 63a 8pt
While it's not as fun as SG's almost-non-upgraded FG rainbow deck (which doesn't work that well against half-bloods if you have NO upgrades, unfortunately), I still find it more fun than mono rush decks. Sometimes you have to think about whether to fractal the vampire or the devourer. Also, it doesn't quite reach a 60% win percentage, unfortunately.
Also, anyone have any decent rainbow decks for half-bloods? I find them more fun to use, but there seems to be a lack of them in the non-upgraded half-blood list (
http://elementscommunity.org/forum/index.php/topic,11027.0.html).