Ge Ramtos is the Guardian of Death. He could be described as a phantom or wraith and somewhat resembles the traditional Grim Reaper, except instead of a skeleton his body seems to be made out of occult artifacts and jewels. Ge Ramtos was available as a summonable rune in the original Wild Arms -- although, oddly, not in the remake -- as well as in Wild Arms 2. He has not had many appearances since then.
Ge Ramtos in Wild Arms
Ge Ramtos in Wild Arms 2