General grievous

I value General Grevious in my crew. I'm (mostly) f2p but I spent a lot of time investing on shards for characters I already had to trade in for the crystals to unlock his shards. It's an uneven exchange and it costs tons more than other characters. When I first got Grevious I was disappointed. He starts out at 4 stars and I didn't see the advantage. When I started investing leveling him up I found that he was a real killer for his ranking. Both his single and multi-attacks take larger hits off the enemy than other characters at the same power level. With only 4 stars, even maxed up he can't keep up with my 7 star characters, but for early rounds in the Galactic War he can take a lot out fast and keep me from wearing down shields on characters I'll need later. And if you can get him to 7 stars and max out his other abilities, you would surely be an attractive ally for top players that would be a real asset to borrow from (not that I have many of opportunities for that with all my levels maxed out, but I'm sure more will be added later).

It also takes less shards to get him to 5 stars than it does to get him. Still, investing in him takes a lot which you could be using to level up a number of characters faster. I tend to trade off, focusing on characters I need to meet a specific goal, and then going back to get him a few more shards. Whether the investment is worth it is something you have to decide.