"Arena is where Heroes get trained and equipped. In training the earn EXP which is important to upgrading their levels. Heroes get more EXP in better Arena."
Opens the training menu where you can set the duration and type of training. This will increase the level of you hero which will add levels to the troop and allow him to equip more items.
Opens the adventure menu where you can boost the stats of your hero by using exploits which u can acquire by attacking normal npcs on war scene.