Crucio Psy is a fun build and pretty easy to find a leech / RM.
i have a lvl 70 Crucio Psy and im takeing on mammoths Lvl 105 in azria..Rather fun char to mess around with:P
Con's to the build:
1.) You have to wait for the monster to attack you takes anywhere from 45 - 60 second to kill on monster
2.) you have to Always have a rm
3.) Requires a full STA build..
4.) Very difficult to lvl at lo lvl's 30-60 " Unless your rich and you got a restat for lvl 60

"
Pro's to the build:
1.) Kills monsters lvl 30+ higher then your own lvl.
2.) 5-15% exp per monster " not includeing Amps "
3.) Fastest lvl char after lvl 60
4.) Requires No Refreshers cuzz you only use your spell every min 10sec's or so
Up to you GL..