I would say an Ibis is the best way to level summoning in terms of Shards used and exp given.
Chat with our AI personalities
The best place to get crimson Charms would be killing the high level cockroaches at the player safety dungeon.
Almost every Monster Drops Gold Charms but you can receive multiple charms from the level 111 Giant Rock Crab in the Chaos Tunnels.
Mithril dragons have a 50% green charm drop rate, dropping four charms each time, which is by far the best. All dragons in general have a fairly good green charm drop rate. The higher level the dragon is, the better change of getting charms. Level 96 cave bugs have an excellent drop rate...considering how weak they are. Cave bugs can be almost as good as mithril dragons, but cave bugs only drop one green charm each time as opposed to the mithril dragons four charm drop each time.
Black d'hide if your a member, green d'hide if you're not.
It would be for low levels- fire drake . Mid levels-summon me. high levels-summon pichu.