Like a masochist, I set my leveling goal to 70. Started the challenge on a Weapon Master and it's not so bad. (Not nearly as fun as Rogue, though.)
I also had the opportunity to get smacked at the Altar of Ascension. It's very challenging.
Well 70 should be relatively easy to get in a month if you play everyday or close to and/or do the weekend events. Weapon Master is a pretty good class to make use of the dragon weapon too, assuming you put it on that. Main issue is making sure you get the right one, iirc it's like Katana and Lightsabers for Weapon Master, though I could be wrong, shit's too complicated for me.
Leveling Elven Knight, pretty fun so far, almost got Chain Rush, I'll get it tomorrow after I pop my FP potion.
I read about a cool way to get additional FP too, though it's like quite boring to do. Basically, I made another account, need a 2nd PC(virtual machines tend to be detected by their shitty anti hack thing, but depends), then you mentor a new char to your main and leave the 2 chars online for a bit(or well, you level the new char for a bit while you're at it). Once you're 4+ in affinity, which takes like a couple of hours of being online together, every 21FP you use on the newb, you gain 1FP on the mentor. Now 1 isn't much, but it's enough for a full dungeon run when you're already at 0. The more time you spend online together, the higher your affinity, the less FP you need to spend to transfer one. I think after like 5hours I'm at affinity 6, which is 16FP. I'll probably leave it overnight, get 8 or so, which is 12FP for 1, which gets really good. Minimum is 10 at 10, but I assume it's slow as shit after some point.
As for clearing that FP, I'm using a Chaos with the event weapon. Chaos is nice cause you don't really need to pay attention, you just mash your summon keys at the start of the dungeon, then you kinda just run from room to room, looting stuff as it explodes until you clear it. That's about all you have to do, at least until higher levels. It's still annoying to constantly have to run dungeons to do 1 run on the main, but I'll use it a bit every now and then to get some free runs.
Other trick is using your mileage. Every dungeon run over lvl 20 you do, you get 1mileage point. You can spend those mileage point in the cash shop(it has a special section). Each of your char is capped at 30mileage points a day, though it's very unlikely you hit the daily cap on a single char since it takes like 6 or more FP per dungeon, I guess using the mentor thing you could. Anyway point is, you get some points. You can buy FP potions with those points. There's 2 types of potions, a 15points one that restores 20FP and a 30points one that restores 50FP. The interesting part is they both have individual cooldowns(at least based on the tooltip, I haven't bought both yesterday as I didn't have enough points), so that's 70FP more everyday, as long as you get 45mileage points. If you play 2 chars, it's pretty easy to do, you get about 20 a char, then you drink the big one and get 5more points from it to buy the 2nd and get some left over points for the day after if you don't want to play your 2nd char as much. Can also buy alchemy crafted FP pots, but they're fairly expensive so meh.