First of all: First post and: It isn't a full brick.

First the specs:
-> HTC Desire
-> rooted
-> s-off'd
-> MIUI-ROM
-> a2sd
-> changed recovery (AMON-RA?)
-> changed mounttable:
/system 128000 kb
/data 294528 kb
/cache 25600 kb
/dev 206024 kb
/mnt/asec/ 206024 kb
/sd-ext 468840 kb
/sdcard 7460008 kb

This is the second time, that Pocket Legends bricked my phone. It is simply fixed via recovery - wiping cache and dalvik-cache.
It seems, that PL spams a little in the dalvik-cache until it is completely full and doesn't let clear this cache.
The dalvik-cache is placed in the data-partition, so it's protected - not like RAM, which cleared, when you reboot.
Maybe it's not your fault - but after some hours in some dungeons (atm Mage lvl. 20 - kill 1024 in baleford) my phone freezes, reboots, and stucked in a bootloop.

So - when this comes the next time: I can give you a logcat-output if you want (I hope it's not stored in the dalvik-cache... )

Best regards, great game,

Mio