Probably it will take on the lore as the bad ending being the true ending.
They could add the giants world and more expand the scope of the game to larger reaches than the kingdoms next to Boletaria.
Bigger weapon variety is also a must, at least give us higher tiered weapons or make unique weapons scale more with high leveled stats.
They could also improve magic by creating a system of tiered magic, or by giving levels to the magics themselves.
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"
